Si8281/82/83/84 Data Sheet ISODrivers with Integrated DC-DC Converters KEY FEATURES The Si828x family (Si8281/82/83/84) is made up of isolated, high-current gate drivers with integrated system safety and feedback functions. These devices are ideal for driving power MOSFETs and IGBTs used in a wide variety of inverter and motor control applications. The Si828x isolated gate drivers utilize Silicon Labs' proprietary silicon isolation technology, supporting up to 5.0 kVrms withstand voltage per UL1577. This technology enables higher-performance, reduced variation with temperature and age, tighter part-topart matching, and superior common-mode rejection compared to other isolated gate driver technologies. In addition to the gate driver, the Si828x family integrates a dc-dc controller for simple implementation of an isolated supply for the driver side. The Si828x dc-dc controller can be ordered in two different configurations depending on what system voltage rails are available and the amount of power needed. The Si8281 and Si8283 have integrated power switch but are limited in dc-dc voltage input to the device bias. The Si8282 and Si8284 utilize and external power switch and are able to accept much higher voltage input power rail. User-adjustable frequency for minimizing emissions, a soft-start function for safety, and a shut-down option are available options. The device requires only minimal passive components and a miniature transformer. The input to the device is a complementary digital input that can be utilized in several configurations. The input side of the isolation also has several control and feedback digital signals. The controller to the device receives information about the driver side power state and fault state of the device and recovers the device from fault through an activelow reset pin. On the output side, Si828x devices provide separate pull-up and pull-down pins for the gate. A dedicated DSAT pin detects the desaturation condition and immediately shuts down the driver in a controlled manner. The Si828x devices also integrate a Miller clamp to facilitate a strong turn-off of the power switch. * System Safety Features * DESAT detection * FAULT feedback * Undervoltage Lock Out (UVLO) * Soft shutdown on fault condition * Silicon Labs' high-performance isolation technology * Industry leading noise immunity * High speed, low latency and skew * Best reliability available * 30 V driver-side supply voltage * Integrated Miller clamp * Power ready pin * Complementary driver control input * Compact packages: 20 and 24-pin widebody SOIC * Integrated DC-DC converter * Feedback-controlled converter with dithering for low EMI * DC-DC converter efficiency of 83% * Shutdown, frequency, and soft-start controls * Industrial temp range: -40 to 125 C Applications * IGBT/ MOSFET gate drives * Industrial, HEV, and renewable energy inverters * AC, Brushless, and DC motor controls and drives * Variable-speed motor controllers * Isolated switch mode and UPS power supplies Safety Regulatory Approvals (Pending) * UL 1577 recognized * Up to 5000 VRMS for 1 minute * CSA component notice 5A approval * IEC 60950-1 (reinforced insulation) * VDE certification conformity * VDE0884 Part 10 (basic insulation) * CQC certification approval * GB4943.1 (reinforced insulation) silabs.com | Building a more connected world. Rev. 1.0 Table of Contents 1. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Isolation Channel Description . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Device Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4 Driver Side Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.5 Fault (FLTb) Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.6 Reset (RSTb) Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.7 Ready (RDY) Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.8 Undervoltage Lockout (UVLO) . . . . . . . . . . . . . . . . . . . . . . . . 6 2.9 Desaturation Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.10 Soft Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.11 Miller Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.12 DC-DC Converter Application Information . . . . . . 2.12.1 External Transformer Driver. . . . . . . . . 2.12.2 Output Voltage Control . . . . . . . . . . 2.12.3 Compensation . . . . . . . . . . . . . 2.12.4 Thermal Protection. . . . . . . . . . . . 2.12.5 Cycle Skipping . . . . . . . . . . . . . 2.12.6 Shutdown (Si8283 and Si8284 Only). . . . . . 2.12.7 Soft Start (Si8283 and Si8284 Only) . . . . . . 2.12.8 Programmable Frequency (Si8283 and Si8284 Only) 2.12.9 Low Supply Voltage Configuration . . . . . . 2.12.10 High Supply Voltage Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 . 9 . 9 . 9 .10 .10 .10 .10 .10 .11 .12 2.13 Transformer Design . . . . . . . . . . . . . .13 . . . . . . . . . . . . . . . . . . 3. Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.1 Recommended Application Circuits. 3.1.1 Inputs . . . . . . . . 3.1.2 Reset, RDY, and Fault . . . 3.1.3 Desaturation . . . . . . 3.1.4 Driver Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 .15 .16 .16 .16 3.2 Layout Considerations . . . . . . . . . . . . . . . . . . . . . . . .16 3.3 Power Dissipation Considerations . . . . . . . . . . . . . . . . . . . . . . .17 4. Electrical Specifications 4.1 Timing Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 . . . . . . . . . . . . . . . . . . . . . . .26 4.2 Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . .27 4.3 Regulatory Information . . . . . . . . . . . . . . . . . . . . . . .31 5. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 silabs.com | Building a more connected world. Rev. 1.0 | 2 6. Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 6.1 Package Outline: 20-Pin Wide Body SOIC . . . . . . . . . . . . . . . . . . . .38 6.2 Land Pattern: 20-Pin Wide Body SOIC . . . . . . . . . . . . . . . . . . . .40 6.3 Package Outline: 24-Pin Wide Body SOIC . . . . . . . . . . . . . . . . . . . .41 6.4 Land Pattern: 24-Pin Wide Body SOIC . . . . . . . . . . . . . . . . . . .43 6.5 Top Marking: 20-Pin and 24-Pin Wide Body SOIC. . . . . . . . . . . . . . . . . .44 7. Revision History 7.1 Revision 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 . . . . silabs.com | Building a more connected world. . . . . . . . . . . . . . . . . . . . . . . . . . .45 Rev. 1.0 | 3 Si8281/82/83/84 Data Sheet Ordering Guide 1. Ordering Guide Ordering UVLO Part Number Voltage (OPN) DC/DC Features Shutdown Soft Start Frequency Control External Switch Insulation Rating Package Available Now Si8281BC-IS 9V No No No No 3.75 kVrms WB SOIC-20 Si8281CC-IS 12 V No No No No 3.75 kVrms WB SOIC-20 Si8282BC-IS 9V No No No Yes 3.75 kVrms WB SOIC-20 Si8282CC-IS 12 V No No No Yes 3.75 kVrms WB SOIC-20 Si8283BC-IS 9V Yes Yes Yes No 3.75 kVrms WB SOIC-24 Si8283CC-IS 12 V Yes Yes Yes No 3.75 kVrms WB SOIC-24 Si8284BC-IS 9V Yes Yes Yes Yes 3.75 kVrms WB SOIC-24 Si8284CC-IS 12 V Yes Yes Yes Yes 3.75 kVrms WB SOIC-24 Si8281BD-IS 9V No No No No 5.0 kVrms WB SOIC-20 Si8281CD-IS 12 V No No No No 5.0 kVrms WB SOIC-20 Si8282BD-IS 9V No No No Yes 5.0 kVrms WB SOIC-20 Si8282CD-IS 12 V No No No Yes 5.0 kVrms WB SOIC-20 Si8283BD-IS 9V Yes Yes Yes No 5.0 kVrms WB SOIC-24 Si8283CD-IS 12 V Yes Yes Yes No 5.0 kVrms WB SOIC-24 Si8284BD-IS 9V Yes Yes Yes Yes 5.0 kVrms WB SOIC-24 Si8284CD-IS 12 V Yes Yes Yes Yes 5.0 kVrms WB SOIC-24 Sample Now Note: 1. Add an "R" at the end of the Part Number to denote Tape and Reel option. 2. All packages are RoHS-compliant with peak solder reflow temperatures of 260C according to the JEDEC industry standard classifications. 3. "Si" and "SI" are used interchangeably. 4. AEC-Q100 qualified. silabs.com | Building a more connected world. Rev. 1.0 | 4 Si8281/82/83/84 Data Sheet System Overview 2. System Overview 2.1 Isolation Channel Description The operation of an Si828x channel is analogous to that of an optocoupler and gate driver, except an RF carrier is modulated instead of light. This simple architecture provides a robust isolated data path and requires no special considerations or initialization at start-up. A simplified block diagram for a single Si828x channel is shown in the figure below. Transmitter Receiver RF OSCILLATOR Input Logic A MODULATOR VDD SemiconductorBased Isolation Barrier VH DEMODULATOR + NOISE FILTER VL Gnd Figure 2.1. Simplified Channel Diagram A channel consists of an RF Transmitter and RF Receiver separated by a semiconductor-based isolation barrier. Referring to the Transmitter, input A modulates the carrier provided by an RF oscillator using on/off keying. The Receiver contains a demodulator that decodes the input state according to its RF energy content and applies the result to output B via the output driver. This RF on/off keying scheme is superior to pulse code schemes as it provides best-in-class noise immunity, low power consumption, and better immunity to magnetic fields. 2.2 Device Behavior The following table shows state relationships for the Si828x inputs and outputs. Table 2.1. Si8281/82/83/84 Truth Table IN+ IN- VDDA State VDDB-VMID State Desaturation State VH VL RDY FLTb H H Powered Powered Undetected Hi-Z Pull-down H H H L Powered Powered Undetected Pull-up Hi-Z H H L X Powered Powered Undetected Hi-Z Pull-down H H X X Powered Unpowered -- -- -- L H X X Powered Powered Detected Hi-Z Pull-down1 H L Note: 1. Driver state after soft shutdown. silabs.com | Building a more connected world. Rev. 1.0 | 5 Si8281/82/83/84 Data Sheet System Overview 2.3 Input The IN+ and IN- inputs to the Si828x devices act as a complementary pair. If the IN- is held low, the IN+ will act as a active-high input for the driver control. Alternatively, if IN+ is held high, then the IN- can be used as an active-low input for driver control. When the IN- is used as the control signal, taking the IN+ low will hold the output driver low. HIGH IN+ LOW IN _ HIGH LOW VH Pull-up Hi-Z Hi-Z VL Pull-down Figure 2.2. Si828x Complementary Input Diagram 2.4 Driver Side Output The Si828x has separate pins for gate drive high (VH) and gate drive low (VL). This makes it simple for the user to use different gate resistors to control IGBT VCE rise and fall time. 2.5 Fault (FLTb) Pin FLTb is an open-drain type output. Once the UVLO condition is cleared on the driver side of the device, the FLTb pin is released. A pull-up resistor takes the pin high. When the desaturation condition is detected, the Si828x indicates the fault by bringing the FLTb pin low. FLTb stays low until the controller brings the RSTb pin low. FLTb is also taken low if the UVLO condition is met during device operation. FLTb is released in that case as soon as the UVLO condition is cleared. 2.6 Reset (RSTb) Pin The RSTb pin is used to clear the desaturation condition and bring the Si828x driver back to an operational state. Even though the input may be toggling, the driver will not change state until the fault condition has been reset. 2.7 Ready (RDY) Pin The ready pin indicates to the controller that power is available on both sides of the isolation, i.e., at VDDA and VDDB. RDY goes high when both the primary side and secondary side UVLO circuits are disengaged. If the UVLO conditions are met on either side of the isolation barrier, the ready pin will return low. RDY is a push-pull output pin and can be floated if not used. 2.8 Undervoltage Lockout (UVLO) The UVLO circuit unconditionally drives VL low when VDDB is below the lockout threshold. The Si828x is maintained in UVLO until VDDB rises above VDDBUV+. During power down, the Si828x enters UVLO when VDDB falls below the UVLO threshold plus hysteresis (i.e., VDDB < VDDBUV+ - VDDBHYS). silabs.com | Building a more connected world. Rev. 1.0 | 6 Si8281/82/83/84 Data Sheet System Overview 2.9 Desaturation Detection The Si828x provides sufficient voltage and current to drive and keep the IGBT in saturation during on time to minimize power dissipation and maintain high efficiency operation. However, abnormal load conditions can force the IGBT out of saturation and cause permanent damage to the IGBT. To protect the IGBT during abnormal load conditions, the Si828x detects an IGBT desaturation condition, shuts down the driver upon detecting a fault, and provides a fault indication to the controller. These integrated features provide desaturation protection with minimum external BOM cost. The figure below illustrates the Si828x desaturation circuit. When the Si828x driver output is high, the internal current source is on, and this current flows from the DSAT pin to charge the CBL capacitor. The voltage on the DSAT pin is monitored by an internal comparator. Since the DSAT pin is connected to the IGBT collector through the DDSAT and a small RDSAT, its voltage is almost the same as the VCE of the IGBT. If the VCE of the IGBT does not drop below the Si828x desaturation threshold voltage within a certain time after turning on the IGBT (blanking period) the block will generate a fault signal. The Si828x desaturation hysteresis is fixed at 220 mV and threshold is nominally 7 V. Ich Driver Control Signal g DDSAT RDSAT DSAT CBL Fault Signal DESAT Sense Driver Disable 7V VMID Figure 2.3. Desaturation Circuit As an additional feature, the block supports a blanking timer function to mask the turn-on transient of the external switching device and avoid unexpected fault signal generation. This function requires an external blanking capacitor, CBL, of typically 390 pF between DSAT and VMID pins. The block includes a 1 mA current source (IChg) to charge the CBL. This current source, the value of the external CBL, and the programmed fault threshold, determine the blanking time (tBlanking). t Blanking = C BL x V DESAT I chg An internal nmos switch is implemented between DSAT and VMID to discharge the external blanking capacitor, CBL, and reset the blanking timer. The current limiting RDSAT resistor protects the DSAT pin from large current flow toward the IGBT collector during the IGBT's body diode freewheeling period (with possible large collector's negative voltage, relative to IGBT's emitter). 2.10 Soft Shutdown To avoid excessive dV/dt on the IGBT's collector during fault shut down, the Si828x implements a soft shut down feature to discharge the IGBT's gate slowly. When soft shut down is activated, the high power driver goes inactive, and a weak pull down via VH and external RH discharges the gate until the gate voltage level is reduced to the VSSB + 2 V level. The high power driver is then turned on to clamp the IGBT gate voltage to VMID. After the soft shut down, the Si828x driver output voltage is clamped low to keep the IGBT in the off state. silabs.com | Building a more connected world. Rev. 1.0 | 7 Si8281/82/83/84 Data Sheet System Overview 2.11 Miller Clamp IGBT power circuits are commonly connected in a half bridge configuration with the collector of the bottom IGBT tied to the emitter of the top IGBT. When the upper IGBT turns on (while the bottom IGBT is in the off state), the voltage on the collector of the bottom IGBT flies up several hundred volts quickly (fast dV/dt). This fast dV/dt induces a current across the IGBT collector-to-gate capacitor (CCG that constitutes a positive gate voltage spike and can turn on the bottom IGBT. This behavior is called Miller parasitic turn on and can be destructive to the switch since it causes shoot through current from the rail right across the two IGBTs to ground. The Si828x Miller clamp's purpose is to clamp the gate of the IGBT device being driven by the Si828x to prevent IGBT turn on due to the collector CCG coupling. VDDB Driver Control CCG VH RSS Soft Shutdown VL VSSB RH RL Driver Control VSSB CLMP 2.0 V VSSB Figure 2.4. Miller Clamp Device The Miller clamp device (Clamp) is engaged after the main driver had been on (VL) and pulled IGBT gate voltage close to VSSB, such that one can consider the IGBT being already off. This timing prevents the Miller clamp from interfering with the driver's operation. The engaging of the Miller Clamp is done by comparing the IGBT gate voltage with a 2.0 V reference (relative to VSSB) before turning on the Miller clamp NMOS. silabs.com | Building a more connected world. Rev. 1.0 | 8 Si8281/82/83/84 Data Sheet System Overview 2.12 DC-DC Converter Application Information The Si828x isolated dc-dc converter is based on a modified fly-back topology and uses an external transformer and rectifying diodes for low cost and high operating efficiency. The PWM controller operates in closed-loop, current mode control and generates isolated output voltages with up to 2 W average output power at VDDP = 5.0 V. Voltage feedback is referenced between VDDB-VSSB. Although there is only one voltage feedback path, two output voltages are realized by the tight coupling of the two secondary transformer windings. Options are available for 24 Vdc input operation and externally configured switching frequency. The dc-dc controller modulates a pair of internal, primary-side power switches (see Figure 2.5 Si8281/83 Block Diagram: 3 to 5 V Input to Split Voltage Output on page 11) to generate an isolated voltage at external diode D1 and D2. Divider resistors, R1 and R2, generate proper 1.05 V for the VSNS pin. Closed-loop feedback is provided by an internal compensated error amplifier, which compares the voltage at the VSNS pin to an internal voltage reference. The resulting error voltage is fed back across the isolation barrier via an internal feedback path to the controller, thus completing the control loop. For input supply voltages higher than 5 V, an external FET Q2 is modulated by a driver pin ESW as shown in Figure 2.6 Si8282/84 Block Diagram: >5.5 V Input to Split Voltage Output on page 12. A shunt resistor based voltage sense pin, RSN, provides current sensing capability to the controller. The Vin must be able to support the Si828x VDDB-VSSD static load current (approximately 9 mA), the output drive load requirement, and the dc-dc power dissipation (loss). The driver power requirement is dependent on the IGBT gate charge and the driver switching frequency. Below are the equations to calculate the Vin power requirement. Pvin = (9 x 10-3 x (VDDB + VSSB) + Qg x Fsw ) where: Qg = IGBT total gate charge Fsw = driver switching frequency = dc-dc efficiency (approximately 78%) Additional part number features include an externally-triggered shutdown of the converter functionality using the SH pin and a programmable soft start configured by a capacitor connected to the SS pin. The resistor value on pin SH/FC and the capacitor value on pin SS are used during power-up to set the dc-dc switching frequency. Note that pin SH/FC and SS pins are available on the Si8283 and Si8284 only. The Si828x can be used with a low-voltage power rail or a high-voltage power rail. These features and configurations are explained in more detail in other sections. 2.12.1 External Transformer Driver The dc-dc controller has internal switches (VSW) for driving the transformer with up to a 5.5 V voltage supply. For higher voltages on the primary side, a driver output (ESW) is provided on the Si8282 and Si8284 that can switch an external NMOS power transistor for driving the transformer. When this configuration is used, a shunt resistor based voltage sense pin (RSN) provides current sensing to the controller. 2.12.2 Output Voltage Control The isolated output voltage, VOUT (VDDB-VSSB), is sensed by a resistor divider that provides feedback to the controller through the VSNS pin. The voltage error is encoded and transmitted back to the primary side controller across the isolation barrier, which in turn changes the duty cycle of the transformer driver. The equation for VOUT is as follows: ( VOUT = VSNS x 1 + R1 R2 ) The VDDB-VSSB voltage split is depended on the ratio of the two secondary windings and can be calculated as follows: ( S 1S1x S2 ) S2 VSSB - VMID = VOUT x ( S1 + S2 ) VDDB - VMID = VOUT x 2.12.3 Compensation The dc-dc converter operates in current mode control. The loop is compensated by connecting an external resistor in series with a capacitor from the COMP pin to VSSB. The compensation network, RCOMP, and CCOMP are set to 200 k and 1 nF for most Si828x applications. silabs.com | Building a more connected world. Rev. 1.0 | 9 Si8281/82/83/84 Data Sheet System Overview 2.12.4 Thermal Protection A thermal shutdown circuit is implemented to protect the system from over-temperature events. The thermal shutdown is activated at a junction temperature that prevents permanent damage from occurring. 2.12.5 Cycle Skipping Cycle skipping is included to reduce switching power losses at light loads. This feature is transparent to the user and is activated automatically at light loads. The product options with integrated power switches (Si8281/83) may never experience cycle skipping during operation, even at light loads, while the external power switch options (Si8282/84) are likely to have cycle skipping start at light loads. 2.12.6 Shutdown (Si8283 and Si8284 Only) This feature allows the operation of the dc-dc converter to be shut down when SH/FC is asserted high. This pin normally has a resistor to ground, the value of which is used in conjunction with the value of the capacitor on the SS pin during startup to determine the dc-dc switching frequency. Therefore, a GPIO pin connected to SH/FC pin to control the shutdown function should be in a high-impedance state during startup to avoid interfering with the internal frequency calculation circuit. During normal operation, this pin should be held low and only taken high to assert dc-dc shutdown. 2.12.7 Soft Start (Si8283 and Si8284 Only) The dc-dc controller has an internal timer that controls the power conversion start-up to limit inrush current. There is also a Soft Start option where users can program the soft start up by an external capacitor connected to the SS pin. The soft start period is the maximum duration of time that the Si8283/84 will try to ramp up the output voltage. If the output voltage fails to reach the targeted voltage level within this soft start period, the Si8283/84 will terminate the dc-dc startup cycle and wait for 40 seconds before initiating a new (startup) cycle. The equations for setting the soft start period are as follows: tSS = 200000 x CSS or CSS = tSS 200000 2.12.8 Programmable Frequency (Si8283 and Si8284 Only) The frequency of the PWM modulator is set to a default of 250 kHz for Si828x. Users can program their desired frequency within a given band of 200 kHz to 800 kHz by controlling the time constant of an external RC connected to the SH_FC and SS pins. The equations for setting fSW or RSW are as follows: f SW = 1025.5 x C SS ) (RSW or RSW = 1025.5 x C SS ) ( f SW The following are the recommended steps for calculating CSS and RSW: 1. Select the maximum soft start duration (typically 40 ms). 2. Calculate Css using Equation A. 3. Select the dc-dc switching frequency. 4. Calculate RSW using the above equation. silabs.com | Building a more connected world. Rev. 1.0 | 10 Si8281/82/83/84 Data Sheet System Overview 2.12.9 Low Supply Voltage Configuration The low supply voltage configuration is used when 3.0 V to 5.5 V supply rails are available. All product options of the Si8281 and Si8283 are intended for this configuration. The output voltage is rted for +15 V / -9 V. An advantage of Si828x devices over other converters that use this same topology is that the output voltage is sensed on the secondary side without requiring additional optocouplers and support circuitry to bias those optocouplers. This allows the dc-dc to operate with superior line and load regulation while reducing external components and increasing lifetime reliability. In a typical isolated gate driver application, the dc-dc powers the Si8281 and Si8283 VDDB and VSSB as shown in the figure below. The Si8281 and Si8283 dc-dc circuit in the figure below can deliver up to 2 W of output power for Vin = 5 V and 1 W for Vin = 3.3 V. The dc-dc requires an input capacitor, C2, blocking capacitor, C1, transformer, T1, rectifying diodes, D1 and D2, and output capacitors, C26, and C27. Resistors R1 and R2 divide the output voltage to match the internal reerence of the error amplifier. The ratio of the two secondary windings, S1 and S2, splits the output voltage into two portions. The positive VDDB and the negative VSSB with common reference to VMID (IGBT Emitter). ( S1S+1S2 ) S2 VSSB = - VOUT x ( S1 + S2 ) VDDB = VOUT x Type 1 loop compensation made by RCOMP and CCOMP are required at the COMP pin. The combination of RCOMP = 200 k and CCOMP = 1 nF satisfies most Si8281 and Si8283 dc-dc applications. Though it is not necessary for normal operation, we recommend that an RC snubber (not shown) be placed in parallel with the secondary winding to minimize radiated emissions. C1 Vin T1 D2 R2 C27 S2 C2 S1 VMID R1 C26 D1 Si8281/Si8283 VDDA UVLO VDDB VDDP RFSW Power FET DC-DC Controller Power FET SH_FC CMOS Isolation VSW UVLO Freq. Control and Shutdown SS Soft Start CSS RDY HF RX Decoder VSSB VSSB VSNS Error Amp and Compensation COMP RCOMP HF TX DSAT Detection FLTb RSTb HF TX Driver Input Control & Reset Encoder DSAT VMID VH HF RX +IN -IN Encoder CCOMP VL Decoder Miller Clamp CLMP Figure 2.5. Si8281/83 Block Diagram: 3 to 5 V Input to Split Voltage Output silabs.com | Building a more connected world. Rev. 1.0 | 11 Si8281/82/83/84 Data Sheet System Overview 2.12.10 High Supply Voltage Configuration The high supply voltage configuration is used when a higher voltage power supply rail (up to 24 V) is available. All product options of the Si8282 and Si8284 are intended for this configuration. The dc-dc converter uses the isolated flyback topology. With this topology, the switch and sense resistor are external, allowing higher switching voltages. The output voltage is sensed on the secondary side without requiring additional optocouplers and support circuitry to bias those optocouplers. This allows the dc-dc to operate with superior line and load regulation. The figure below shows the block diagram of an Si828x with external components. The Si8284 product option has externally controlled switching frequency and soft start. The dc-dc requires input capacitor C28, transformer T1, switch Q4, sense resistor Rsense, rectifying diodes D1 and D2, and output capacitors C26 and C27. To supply VDDA, Q3 transistor is biased by R23, 5.6 V Zener diode D5 and filtered by C30 and C11. External frequency and soft start behavior is set by CSS and RFSW. Resistors R1 and R2 divide the output voltage to match the internal reference of the error amplifier. The ratio of the two secondary windings splits the output voltage into two portions. The positive VDDB and the negative VSSB with common reference to VMID (IGBT Emitter). ( S1S+1S2 ) S2 VSSB = - VOUT x ( S1 + S2 ) VDDB = VOUT x Type 1 loop compensation made by RCOMP and CCOMP are required at the COMP pin. The combination of RCOMP = 49.9 k and CCOMP = 1.5 nF satisfies most Si8282 and Si8284 dc-dc applications. Though it is not necessary for normal operation, we recommend to use RC snubbers (not shown) on both primary and secondary windings to minimize high-frequency emissions. T1 D2 R2 Vin C27 C28 R23 Q3 R1 C26 D1 Si8282/Si8284 D5 5.6V C30 VDDA UVLO VDDB C11 ESW UVLO FET Driver DC-DC Controller RSN Rsense RFSW GNDP Current Sensing FC_SH Freq. Control and Shutdown SS CSS Soft Start RDY HF RX Decoder CMOS Isolation Q4 VSSB VSSB VSNS Error Amp and Compensation COMP RCOMP HF TX DSAT Detection FLTb RSTb HF TX Driver Input Control & Reset Encoder DSAT VMID VH HF RX +IN -IN Encoder CCOMP VL Decoder Miller Clamp CLMP Figure 2.6. Si8282/84 Block Diagram: >5.5 V Input to Split Voltage Output silabs.com | Building a more connected world. Rev. 1.0 | 12 Si8281/82/83/84 Data Sheet System Overview 2.13 Transformer Design The internal switch dc-dc (Si8281, Si8283) and external switch dc-dc (Si8282, Si8284) operate in different topologies and, thus, require different transformer designs. The table below provides a list of transformers and their parametric characteristics that have been validated to work with Si828x products. It is recommended that users order the transformers from the vendors per the part numbers given below. To manufacture transformers from your preferred suppliers that may not be listed below, please specify to supplier the parametric characteristics as specified in the table below for a given input voltage and isolation rating. Table 2.2. Si828x Recommended Transformers Transformer Supplier Ordering Part # Input Voltage (V) Output Voltage (V) Turns Ratio P:S Leakage Primary Primary Inductance Resistance Inductance (nH max) ( max) Isolation Rating (kVrms) Coilcraft1, 2 (http://www.coilcraft.com) TA7788-AL 7-24 -9.0-15 1 : 1.25 : 0.75 554 25 H 5% 0.49 5 UMEC2 (http://www.umecusa.com) UTB02241s 4.5-5.5 -10.0-14 1:7:5 100 2.5 H 5% 0.05 5 UMEC2 (http://www.umecusa.com) UTB02253s 7-24 -9.0-15 1 : 2 : 1.21 200 25 H 5% 0.225 5 Note: 1. AEC-Q200 qualified. 2. For reference design details, see AN973: Design Guide for Si8281/83 Isolated DC-DC with Internal Switch. silabs.com | Building a more connected world. Rev. 1.0 | 13 Si8281/82/83/84 Data Sheet Applications Information 3. Applications Information The following sections detail the input and output circuits necessary for proper operation. 3.1 Recommended Application Circuits T1 8 D1 VDDB B160 2 Vin S1 6 C26 C2 10uF 100pF 7 C1 3 S2 10uF Lp 5 R13 100 C27 10uF D2 VSSB B160 Place RDSAT, DSAT, CBL as close to Q1 as possible R1 R2 C8 C7 RDSAT 0.1uF 10uF 0.1uF Vin Rsw 10k 10k MCU R8 R9 Css GNDP VSNS VSW COMP VDDP NC VDDA DSAT SH/FC VDDB SS 220nF GNDA RSTb FLTb 100pF 100pF 100 C21 R7 C20 RDY/SSH C22 100pF VH RC 1nF Q1 C12 10uF C13 IN+ NC IN- VSSB CBL 0.1uF RH VL VSSB + RAIL CC 200K RL CLMP VMID DSAT Q2 C14 10uF C15 0.1uF - RAIL Si8281/83 RFC, Css, pin SH/FC, SS are available on Si8283 only Figure 3.1. Recommended Si8281/83 Application Circuit silabs.com | Building a more connected world. Rev. 1.0 | 14 Si8281/82/83/84 Data Sheet Applications Information Vin Auxiliary VDDP to 5V VDDA circuit The components in this box can be removed if 5V source is available to connect to the VDDA directly R14 = (Vin - 5.6)/0.001 Vin = 7V to 24V T1 C28 C31 C13 10uF C30 8 VDDB D1 B160 R23 15K Q3 0.1uF D5 S1 3 100pF 6 R24 C26 C2 10uF 100pF 7 0.1uF 100 5.6V R13 2 MMBT2222LT1 S2 Q4 5 FDT3612 VDDA R22 C11 0.1uF Rsw 10k R8 10k Css 220nF R9 ESW NC VDDA DSAT SH/FC VDDB GNDA RDY C21 C22 as close to Q1 as possible COMP SS Place RDSAT, DDSAT, and CBL R2 RSN VH VL RDSAT DSAT + RAIL RC CC 200K 1nF Q1 C12 10uF C13 CBL 0.1uF RH RL CLMP VMID C14 C15 Q2 VSSB 100pF 100pF C20 VSSB B160 R1 VSNS FLTb R7 25uH GNDP RSTb MCU 100 10uF D2 Rsense 0.1 10.0 Vin C27 100 IN+ IN- NC 10uF 0.1uF - RAIL VSSB 100pF Si8282/84 RFC, Css, pin SH/FC, SS are available on Si8284 only Figure 3.2. Recommended Si8282/84 Application Circuit The Si828x has both inverting and non-inverting gate control inputs (IN- and IN+). In normal operation, one of the inputs is not used, and should be connected to GNDA (IN-) or VDDA (IN+) for proper logic termination. The Si828x has an active low reset input (RSTb), an active high ready (RDY) push pull output, and an open drain fault (FLTb) output that requires a weak 10 k pull-up resistor. The Si828x gate driver will shut down when a fault is detected. It then provides FLTb indication to the MCU, and remains in the shutdown state until the MCU applies a reset signal. The desaturation sensing circuit consisted of the 380 pF blanking capacitor, 100 current limiting resistor, and DSAT diode. These components provide current and voltage protection for the Si828x desaturation DSAT pin and it is critical to place these components as close to the IGBT as possible. Also, on the layout, make sure that the loop area forming between these components and the IGBT be minimized for optimum desaturation detection. The Si828x has VH and VL gate drive outputs with external RH and RL resistors to limit output gate current. The value of these resistors can be adjusted to independently control IGBT collector voltage rise and fall time. The CLMP output should be connected to the gate of the IGBT directly to provide clamping action between the gate and VSSB. This clamping action dissipates IGBT Miller current from collector to the gate to secure the IGBT in the off-state. 3.1.1 Inputs Inputs should be driven by CMOS level push-pull output. If input is driven by the MCU GPIO, it is recommended that the MCU be located as closed to the Si828x as possible to minimize PCB trace parasitic and noise coupling to the input circuit. In noisy environments, it is customary to add a small series resistor, and a decoupling cap to the IN traces (R7, C20 in Figure 3.1 Recommended Si8281/83 Application Circuit on page 14 and Figure 3.2 Recommended Si8282/84 Application Circuit on page 15). These RC filters attenuate glitches from electrical noise and improve input-to-output signal integrity. silabs.com | Building a more connected world. Rev. 1.0 | 15 Si8281/82/83/84 Data Sheet Applications Information 3.1.2 Reset, RDY, and Fault The Si828x has an active high ready (RDY) push pull output, an open drain fault (FLTb) output, and an active low reset input (RSTb) that require pull-up resistors (R8 and R9). Fast common-mode transients in high-power circuits can inject noise and glitches into these pins due to parasitic coupling. Depending on the IGBT power circuit layout, additional capacitance (use 100 pF to 470 pF for C21 and C22) can be included on these pins to prevent faulty RDY and FLTb indications as well as unintended reset to the device. The FLTb outputs from multiple Si828x devices can be connected in an OR wiring configuration to provide a single FLTb signal to the MCU. 3.1.3 Desaturation The desaturation sensing circuit consists of the blanking capacitor (390 pF recommended), 100 current limiting resistor, and DSAT diode. These components provide current and voltage protection for the Si828x desaturation DSAT pin, and it is critical to place these components as close to the IGBT as possible. Also, in the layout, the loop area forming between these components and the IGBT should be minimized for optimum desaturation detection. 3.1.4 Driver Outputs The Si828x has VH and VL gate drive outputs (see Figure 3.1 Recommended Si8281/83 Application Circuit on page 14). They work with external RH and RL resistors to limit output gate current. The value of these resistors can be adjusted to independently control IGBT collector voltage rise and fall time. The CLMP output should be connected to the gate of the IGBT directly to provide clamping action between the gate and VSSB pin. This clamping action dissipates IGBT Miller current from the collector to the gate to secure the IGBT in the off-state. Negative VSSB provides further help to ensure the gate voltage stays below the IGBT's Vth during the off state. 3.2 Layout Considerations It is most important to minimize ringing in the drive path and noise on the supply lines. Care must be taken to minimize parasitic inductance in these paths by locating the Si828x as close as possible to the device it is driving. In addition, the supply and ground trace paths must be kept short. For this reason, the use of power and ground planes is highly recommended. A split ground plane system having separate ground and power planes for power devices and small signal components provides the best overall noise performance. silabs.com | Building a more connected world. Rev. 1.0 | 16 Si8281/82/83/84 Data Sheet Applications Information 3.3 Power Dissipation Considerations Proper system design must assure that the Si828x operates within safe thermal limits across the entire load range. The Si828x total power dissipation is the sum of the power dissipated by bias supply current, internal parasitic switching losses, and power dissipated by the series gate resistor and load. Equation 1 shows total Si828x power dissipation. PD = (VDDA)(IDDA) + 1.05(VDDB)(IDDB) + 1.05 x f x Qint x VDDB + 1.05 Rp Rn f Q (VDDB) + 2 ( )( IGBT ) Rp + RH Rn + RL where: PD is the total Si828x device power dissipation (W). IDDA is the input-side maximum bias current (7.5 mA). IDDB is the driver die maximum bias current (10.8 mA). Qint is the internal parasitic charge (3 nC). VDDA is the input-side VDD supply voltage (2.7 to 5.5 V). VDDB is the total driver-side supply voltage (VDDB + VSSB: 12.5 to 30 V). f is the IGBT switching frequency (Hz). RH is the VH external gate resistor, RL is the VL external gate resistor. Rp is the RDS(ON) of the driver pull-up switch: (2.6 ). Rn is the RDS(ON) of the driver pull-down switch: (0.8 ). Equation 1. To account for the Si828x dc-dc loss, an additional 5% of power is added to the driver-side circuit (VDDB). The maximum power dissipation allowable for the Si828x is a function of the package thermal resistance, ambient temperature, and maximum allowable junction temperature, as shown in Equation 2: PDmax Tjmax - TA ja where: PDmax = Maximum Si828x power dissipation (W). Tjmax = Si828x maximum junction temperature (150 C). TA = Ambient temperature (C) ja = Si828x junction-to-air thermal resistance (60 C/W for four-layer PCB) f = Si828x switching frequency (Hz) Equation 2. Substituting values for PDmax Tjmax (150 C), TA (125 C), and ja (60 C/W) into Equation 2 results in a maximum allowable total power dissipation of 0.42 W. PDmax silabs.com | Building a more connected world. 150 - 125 = 0.42W 60 Rev. 1.0 | 17 Si8281/82/83/84 Data Sheet Applications Information Maximum allowable load is found by substituting this limit and the appropriate data sheet values from Table 4.1 into Equation 1 and simplifying. The result is Equation 3. PD = (VDDA)(IDDA) + 1.05(VDDB)(IDDB) + 1.05 x f x Qint x VDDB + 1.05 Rp Rn f Q (VDDB) + 2 ( )( L ) Rp + RH Rn + RL ( )( )(VDDB2) RpRp+ RH + Rn Rn+ RL 1.05 2.6 0.8 0.42 = (VDDA)(0.0075) + 1.05(VDDB)(0.0108) + 1.05 x f x 3 x 10-9 x VDDB + f C VDDB 2) + 2 ( )( L )( 2.6 + 15 0.8 + 10 PD = (VDDA)(IDDA) + 1.05(VDDB)(IDDB) + 1.05 x f x Qint x VDDB + 1.05 f CL 2 0.42 - (VDDA)(0.0075) - 1.05(VDDB)(0.0108) - 1.05 x f x 3 x 10-9 x VDDB = 0.117VDDB 2 f (C L CL = 0.42 - (VDDA x 7.5 x 10-3) - (VDDB x 10.8 x 10-3) 0.117 x VDDB 2( f ) - ) 2.692 x 10-8 VDDB Equation 3. Below is an example power dissipation calculation for the Si828x driver using Equation 1 with the following givens: VDDA = 5.0 V VDDB = 18 V f = 30 kHz RH = 10 RL = 15 QG = 85 nC PD = (5)(0.0075) + 1.05(18)(0.0108) + 1.05(2 x 104)(3 x 10-9)(18) + ( )( )( ) 1.05 2.6 0.8 3 x 104 85 x 10-9 18 + = 242mW 2 2.6 + 10 0.8 + 15 The driver junction temperature is calculated using Equation 2, where: Pd is the total Si828x device power dissipation (W) ja is the thermal resistance from junction to air (60 C/W in this example) TA is the maximum ambient temperature (125 C) Tj = Pd x ja + TA Tj = (0.242) x (60) + 125 = 139.5C Calculate maximum loading capacitance from equation 3: 1. VDDA = 5 V and (VDDB-VSSB) = 12.5 V. CL = 1.51 x 10-2 - 2.15 x 10-9 f CL = 5.91 x 10-3 - 1.5 x 10-9 f 2. VDDA = 5 V and (VDDB-VSSB) = 18 V. 3. VDDA = 5 V and (VDDB-VSSB) = 30 V. CL = 1.04 x 10-3 - 8.97 x 10-10 f Graphs are shown in the following figure. All points along the load lines in these graphs represent the package dissipation-limited value of CL for the corresponding switching frequency. silabs.com | Building a more connected world. Rev. 1.0 | 18 Si8281/82/83/84 Data Sheet Applications Information Figure 3.3. Maximum Load vs. Switching Frequency (25 C) silabs.com | Building a more connected world. Rev. 1.0 | 19 Si8281/82/83/84 Data Sheet Electrical Specifications 4. Electrical Specifications Table 4.1. Electrical Specifications VIN = 24 V; VDDA = 4.3 V (See Figure 3) for all Si8282/84; VDDA = VDDP = 3.0 to 5.0 V (See Figure 2) for all Si8281/83; TA = -40 to +125 C unless otherwise noted. Parameter Symbol Test Condition Min Typ Max Units DC Parameters Input Supply Voltage VDDA 2.8 -- 5.5 V Power Input Voltage VDDP 3.0 -- 5.5 V (VDDB - VSSB) 9.5 -- 30 V (VMID - VSSB) 0 -- 15 V IDDA(Q) -- 6.8 7.5 mA -- 10.5 -- mA IDDB(Q) -- 8.7 10.8 mA FSW -- 250 -- kHz 180 200 220 kHz 450 500 550 kHz 810 900 990 kHz 1.002 1.05 1.097 V -500 -- 500 nA -5 -- +5 % -- 1 -- mV/V ILOAD = 50 to 400 mA -- 0.1 -- % ILOAD = 100 mA -- 100 -- mV p-p CIN = COUT = 0.1 F in parallel with 10 F -- 2 -- % Driver Supply Voltage Input Supply Quiescent Current Input Supply Active Current Output Supply Quiescent Current IDDA f = 10 kHz DC-DC Converter Switching Frequency Si8281, Si8282 RFSW = 23.3 k FSW = 1025.5/(RFSW x CSS) CSS = 220 nF (1% tolerance on BOM) Switching Frequency Si8283, Si8284 FSW RFSW = 9.3 k FSW = 1025.5/(RFSW x CSS) CSS = 220 nF (1% tolerance on BOM) RFSW = 5.18 k CSS = 220 nF VSNS Voltage VSNS VSNS Current Offset Ioffset Output Voltage Accuracy ILOAD = 0 A ILOAD = 0 mA Line Regulation VOUT(line)/ VDDP Load Regulation VOUT(load)/ VOUT ILOAD = 50 mA VDDP varies from 4.5 to 5.5 V Output Voltage Ripple Si8281, Si8283 Si8282, Si8284 Turn-on overshoot VOUT(start) ILOAD = 0 A silabs.com | Building a more connected world. Rev. 1.0 | 20 Si8281/82/83/84 Data Sheet Electrical Specifications Parameter Symbol Test Condition Min Typ Max Units Continuous Output Current Si8281, Si8283 84 5.0 V to +15 V / -9 V split rails 3.3 V to +15 V / -9 V split rails ILOAD(max) mA 84 Si8282, Si8284 84 24 V to +15 V / -9 V split rails Cycle-by-Cycle Average Current Limit Si8281, Si8283 No-Load Supply Current IDDP Si8281, Si8283 No-Load Supply Current IDDA Si8281, Si8283 No-Load Supply Current IDDP Si8282, Si8284 No-Load Supply Current IDDA Si8282, Si8284 ILIM IDDPQ_DCDC IDDAQ_DCDC IDDPQ_DCDC IDDAQ_DCDC Output short circuited VDDP = VDDA = 5 V VDDP = VDDA = 5 V VIN = 24 V VIN = 24 V -- -- -- -- -- 3 30 5.7 0.8 5.8 -- A -- mA -- mA -- mA -- mA -- % -- ms Peak Efficiency Si8281, Si8283 -- Si8282, Si8284 78 83 Soft Start Time, Full Load Si8281, Si8282 tSST -- Si8283, Si8284 25 50 tOTP -- 21 -- s High Drive Transistor RDS(ON) ROH -- 2.48 -- Low Drive Transistor RDS(ON) ROL -- 0.86 -- High Drive Peak Output Current IOH 2.5 2.8 -- A Low Drive Peak Output Current IOL 3.0 3.4 -- A Restart Delay from Fault Event Drive Parameters VH = VDDB - 15 V TPW_IOH < 250 ns VL = VSSB + 6.0 V TPW_IOL< 250 ns UVLO Parameters UVLO Threshold + VDDAUV+ 2.4 2.7 3.0 UVLO Threshold - VDDAUV- 2.3 2.6 2.9 UVLO Lockout Hysteresis- (Input Side) VDDAHYS -- 100 -- silabs.com | Building a more connected world. mV Rev. 1.0 | 21 Si8281/82/83/84 Data Sheet Electrical Specifications Parameter Symbol Test Condition Min Typ Max Units 8.0 9.0 10.0 V 10.8 12.0 13.2 V 7.0 8.0 9.0 V 9.8 11.0 12.2 V VDDBHYS -- 1 -- V UVLO+ to RDY High Delay tUVLO+ to RDY -- 100 s ULVO- to RDY Low Delay tUVLO- to RDY -- 0.79 s UVLO Threshold + (Driver Side) 9 V Threshold (Si828xBD) VDDBUV+ 12 V Threshold (Si828xCD) UVLO Threshold - (Driver Side) 9 V Threshold (Si828xBD) VDDBUV- 12 V Threshold (Si828xCD) UVLO lockout hysteresis (Driver Side) Desaturation Detector Parameters DESAT Threshold VDDB - VSSB > 6.5 6.9 7.3 V IChg -- 1 -- mA DESAT Sense to 90% VOUT Delay tDESAT(90%) -- 220 300 ns DESAT Sense to 10% VOUT Delay tDESAT(10%) 0.77 2.5 2.7 s DESAT Sense to FLT Low Delay tDESAT to FLT -- 220 300 ns tRST to FLT -- 37 45 ns Vt Clamp -- 2.0 -- V Miller Clamp Transistor RDS (ON) RMC -- 1.07 -- Clamp Low Level Sinking Current ICL 3.0 3.4 -- A CBl charging current Reset to FLT High Delay VDESAT VDDBUV+ Miller Clamp Parameters (Si8285 Only) Clamp Pin Threshold Voltage VCLMP = VSSB + 6.0 Digital Parameters Logic High Input Threshold VIH 2.0 -- -- V Logic Low Input Threshold VIL -- -- 0.8 V VIHYST -- 440 -- mV Input Hysteresis High Level Output Voltage (RDY pin only) VOH IO = -4 mA VDDA - 0.4 -- -- V Low Level Output Voltage (RDY pin only) VOL IO = 4 mA -- -- 0.4 V -- -- 200 mV VDDA = 5 V, Open-Drain Low Level Output Voltage (FLT pin only) 5 k pull-up resistor AC Switching Parameters Propagation Delay (Low-to-High) tPLH CL = 200 pF 30 40 50 ns Propagation Delay (High-to-Low) tPHL CL = 200 pF 30 40 50 ns Pulse Width Distortion PWD |tPLH - tPHL| -- 1 5 ns Propagation Delay Difference4 PDD tPHLMAX - tPLHMIN -1 -- 25 ns tR CL = 200 pF -- 5.5 15 ns Rise Time silabs.com | Building a more connected world. Rev. 1.0 | 22 Si8281/82/83/84 Data Sheet Electrical Specifications Parameter Symbol Test Condition Min Typ Max Units tF CL = 200 pF -- 8.5 20 ns Output = low or high (VCM = 1500 V) 35 50 -- kV/s Fall Time Common Mode Transient Immunity 1. See Ordering Guide for more information. 2. Minimum value of (VDD - GND) decoupling capacitor is 1 F. 3. When performing this test, it is recommended that the DUT be soldered to avoid trace inductances, which may cause overstress conditions. 4. Guaranteed by characterization. IIN IOUT + 10 F T1 + B160 VIN 100 _ 10 F 10 F 100 pF UTB02174S IDDP VMID VDDP VDDB ISOLATION VDDA SH _ B160 VSW IDDA 10 F VOUT IDDB 182 k VSNS COMP 200 k GNDA GNDP 7.87 k VSSB 1 nF Figure 4.1. Si8281, Si8283 Measurement Circuit for Converter Efficiency and Regulation silabs.com | Building a more connected world. Rev. 1.0 | 23 Si8281/82/83/84 Data Sheet Electrical Specifications IDDP IIN IOUT T1 + VIN _ + B160 IDDA 100 100 10 F 10 F 100 pF 100pF FDT3612 15 k B160 VMID RSNS IDDB 0.1 BZT52C5V6S-F-7 VDDB GNDP VDDA 0.1 F SS ISOLATION 0.1 F _ UTB02246s ESW MMBT2222LT1 10 F VOUT 182 k VSNS COMP 200 k 8.66 k SH_FC 0.22 F 18.7 k VSSB 1 nF GNDA Figure 4.2. Si8282, Si8284 Measurement Circuit for Converter Efficiency and Regulation Figure 4.3. Common-Mode Transient Immunity Characterization Circuit silabs.com | Building a more connected world. Rev. 1.0 | 24 Si8281/82/83/84 Data Sheet Electrical Specifications Table 4.2. Absolute Maximum Ratings1 Parameter Symbol Min Max Unit Storage Temperature TSTG -65 +150 C Operating Temperature TA -40 +125 C Junction Temperature TJ -- +140 C Peak Output Current (tPW = 10 s) IOPK -- 4.0 A Supply Voltage VDD -0.5 36 V Output Voltage VOUT -0.5 36 V Input Power Dissipation PI -- 100 mW Output Power Dissipation PO -- 800 mW Total Power Dissipation (All Packages Limited by Thermal Derating Curve) PT -- 900 mW Lead Solder Temperature (10 s) -- 260 C HBM Rating ESD 4 -- kV CDM 1600 -- V Maximum Isolation (Input to Output) (1 sec) -- 6500 VRMS Note: 1. Permanent device damage may occur if the absolute maximum ratings are exceeded. Functional operation should be restricted to the conditions as specified in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. silabs.com | Building a more connected world. Rev. 1.0 | 25 Si8281/82/83/84 Data Sheet Electrical Specifications 4.1 Timing Diagrams UVLO Threshold + UVLO Threshold - VDDB - VMID tUVLO- to RDY tUVLO+ to RDY VDDA RDY GNDA Figure 4.4. UVLO Condition to RDY Output VDESAT DSAT tFLT FLTb tDSAT to SS VH VSSB + 2 V VL tRSTb-FLT RSTb Figure 4.5. Device Reaction to Desaturation Event silabs.com | Building a more connected world. Rev. 1.0 | 26 Si8281/82/83/84 Data Sheet Electrical Specifications 4.2 Typical Operating Characteristics silabs.com | Building a more connected world. Rev. 1.0 | 27 Si8281/82/83/84 Data Sheet Electrical Specifications silabs.com | Building a more connected world. Rev. 1.0 | 28 Si8281/82/83/84 Data Sheet Electrical Specifications silabs.com | Building a more connected world. Rev. 1.0 | 29 Si8281/82/83/84 Data Sheet Electrical Specifications silabs.com | Building a more connected world. Rev. 1.0 | 30 Si8281/82/83/84 Data Sheet Electrical Specifications 4.3 Regulatory Information Table 4.3. Regulatory Information1, 2 CSA The Si828x is certified under CSA Component Acceptance Notice 5A. For more details, see Master Contract Number 232873. 60950-1: Up to 600 VRMS reinforced insulation working voltage; up to 1000 VRMS basic insulation working voltage. VDE The Si828x is certified according to VDE0884. For more details, see File 5006301-4880-0001. VDE 0884-10: Up to 1414 Vpeak for basic insulation working voltage. UL The Si828x is certified under UL1577 component recognition program. For more details, see File E257455. Rated up to 5000 VRMS isolation voltage for basic protection. CQC The Si828x is certified under GB4943.1-2011. Rated up to 600 VRMS reinforced insulation working voltage; up to 1000 VRMS basic insulation working voltage. Note: 1. Regulatory Certifications apply to 3.75 and 5.0 kVRMS rated devices, which are production tested to 4.5 and 6.0 kVRMS for 1 sec, respectively. 2. For more information, see 1. Ordering Guide. Table 4.4. Insulation and Safety-Related Specifications Parameter Symbol Test Condition Value WB SOIC Unit Nominal External Air Gap (Clearance)1 CLR 8.0 mm Nominal External Tracking (Creepage) CPG 8.0 mm Minimum Internal Gap (Internal Clearance) DTI 0.016 mm 600 V Tracking Resistance PTI or CTI IEC60112 Erosion Depth ED 0.019 mm Resistance (Input-Output)2 RIO 1012 Capacitance (Input-Output)2 CIO 1 pF f = 1 MHz Note: 1. The values in this table correspond to the nominal creepage and clearance values as detailed in 6.1 Package Outline: 20-Pin Wide Body SOIC and 6.3 Package Outline: 24-Pin Wide Body SOIC. VDE certifies the clearance and creepage limits as 8.5 mm minimum for the WB SOIC. UL does not impose a clearance and creepage minimum for component level certifications. CSA certifies the clearance and creepage limits as 7.6 mm minimum for the WB SOIC package. 2. To determine resistance and capacitance, the Si828x is converted into a 2-terminal device. All pins on input side are shorted together to form the first terminal, and similarly, all pins on the output side are shorted together to form the second terminal. The parameters are then measured between these two terminals. silabs.com | Building a more connected world. Rev. 1.0 | 31 Si8281/82/83/84 Data Sheet Electrical Specifications Table 4.5. IEC 60664-1 Ratings Parameter Specification Test Condition Basic Isolation Group Installation Classification WB SOIC Material Group I Rated Mains Voltages 150 VRMS I-IV Rated Mains Voltages 300 VRMS I-IV Rated Mains Voltages 600 VRMS I-III Table 4.6. VDE 0884 Part 10 Insulation Characteristics1 Parameter Symbol Characteristic Test Condition WB SOIC VIORM Maximum Working Insulation Voltage Unit 1414 V peak VPR Method b1 (VIORM x 1.875 = VPR, 100% Production Test, tm = 1 sec, Partial Discharge < 5 pC) 2652 V peak Transient Overvoltage VIOTM t = 60 sec 8000 V peak Surge Voltage VIOSM Tested per IEC 60065 with surge voltage of 1.2 s/50 s 3077 V peak Input to Output Test Voltage Tested with 4000 V Pollution Degree (DIN VDE 0110, See Table XX.) Insulation Resistance at TS, VIO = 500 V 2 >109 RS Note: 1. Maintenance of the safety data is ensured by protective circuits. The Si828x provides a climate classification of 40/125/21. Table 4.7. IEC Safety Limiting Values1 Parameter Symbol Safety Temperature TS Safety Current IS Output Power PS Test Condition JA = 60 C/W (WB SOIC-20 or SOIC-24) TJ = 140 C, TA = 25 C Max Unit WB SOIC-20 WB SOIC-24 150 150 C 30 30 mA 0.9 0.9 W Note: 1. Maximum value allowed in the event of a failure. 2. The Si828x is tested with RH = RL = 0 , CL = 5 nF, and a 200 kHz, 50% duty cycle square wave input. 3. See Figure 4.6 for Thermal Derating Curve. silabs.com | Building a more connected world. Rev. 1.0 | 32 Si8281/82/83/84 Data Sheet Electrical Specifications Table 4.8. Thermal Characteristics Parameter Symbol IC Junction-to-Air Thermal Resistance JA Typ WB SOIC-20 WB SOIC-24 60 60 Unit C/W Figure 4.6. WB SOIC-20/24 Thermal Derating Curve (Dependence of Safety Limiting Values per VDE) silabs.com | Building a more connected world. Rev. 1.0 | 33 Si8281/82/83/84 Data Sheet Pin Descriptions 5. Pin Descriptions GNDP VSNS GNDP VSNS VSW COMP RSN COMP VDDP NC ESW NC VDDA DSAT VDDA VDDB GNDA VH RSTb FLTb VL FLTb VL RDY CLMP RDY CLMP IN+ VMID IN+ VMID _ VSSB IN _ VSSB GNDA RSTb IN Si8281 DSAT Si8282 VDDB VH Table 5.1. Si8281/82 Pin Descriptions Name Si8281 Pin # Si8282 Pin # Description GNDP 1 1 Power stage ground VSW 2 -- Power stage internal switch RSN -- 2 Power stage current sense VDDP 3 -- Power stage supply ESW -- 3 Power stage external switch drive VDDA 4 4 Input side low voltage power supply GNDA 5 5 Input side low voltage ground RSTb 6 6 Reset fault condition FLTb 7 7 Fault condition signal RDY 8 8 UVLO ready signal IN+ 9 9 Driver control plus IN- 10 10 Driver control minus VSSB 11 11 Output side low voltage power supply VMID 12 12 Drain reference for driven switch CLMP 13 13 Miller clamp VL 14 14 Low gate drive VH 15 15 High gate drive VDDB 16 16 Output side low voltage power supply DSAT 17 17 Desaturation detection input NC1 18 18 No connect COMP 19 19 dc/dc compensation VSNS 20 20 dc/dc voltage feedback silabs.com | Building a more connected world. Rev. 1.0 | 34 Si8281/82/83/84 Data Sheet Pin Descriptions Name Si8281 Pin # Si8282 Pin # Description Note: 1. No Connect. These pins are not internally connected. To maximize CMTI performance, these pins should be connected to the ground plane. silabs.com | Building a more connected world. Rev. 1.0 | 35 Si8281/82/83/84 Data Sheet Pin Descriptions GNDP VSNS GNDP VSNS VSW COMP RSN COMP VDDP NC ESW NC VDDA DSAT VDDA DSAT SH/FC VDDB SH/FC VDDB SS GNDA Si8283 VH SS VL GNDA Si8284 VH VL RSTb CLMP RSTb CLMP FLTb VMID FLTb VMID RDY VSSB RDY VSSB IN+ IN _ NC IN+ VSSB IN NC _ VSSB Table 5.2. Si8283/84 Pin Descriptions Name Si8283 Pin # Si8284 Pin # Description GNDP 1 1 Power stage ground VSW 2 -- Power stage internal switch RSN -- 2 Power stage current sense VDDP 3 -- Power stage supply ESW -- 3 Power stage external switch drive VDDA 4 4 Input side low voltage power supply SH/FC 5 5 Shutdown and Switch frequency control SS 6 6 Soft startup control GNDA 7 7 Input side low voltage ground RSTb 8 8 Reset fault condition FLTb 9 9 Fault condition signal RDY 10 10 UVLO ready signal IN+ 11 11 Driver control plus IN- 12 12 Driver control minus VSSB 13, 15 13, 15 Output side low voltage power supply VMID 16 16 Drain reference for driven switch CLMP 17 17 Miller clamp VL 18 18 Low gate drive VH 19 19 High gate drive VDDB 20 20 Output side low voltage power supply DSAT 21 21 Desaturation detection input silabs.com | Building a more connected world. Rev. 1.0 | 36 Si8281/82/83/84 Data Sheet Pin Descriptions Name Si8283 Pin # Si8284 Pin # Description NC1 14, 22 14, 22 No connect COMP 23 23 dc/dc compensation VSNS 24 24 dc/dc voltage feedback Note: 1. No Connect. These pins are not internally connected. To maximize CMTI performance, these pins should be connected to the ground plane. silabs.com | Building a more connected world. Rev. 1.0 | 37 Si8281/82/83/84 Data Sheet Packaging 6. Packaging 6.1 Package Outline: 20-Pin Wide Body SOIC The figure below illustrates the package details for the Si8281/82 in a 20-Pin Wide Body SOIC. The table lists the values for the dimensions shown in the illustration. Figure 6.1. 20-Pin Wide Body SOIC Symbol Millimeters Min Max A -- 2.65 A1 0.10 0.30 A2 2.05 -- b 0.31 0.51 c 0.20 0.33 D 12.80 BSC E 10.30 BSC E1 7.50 BSC e 1.27 BSC L 0.40 1.27 h 0.25 0.75 0 8 silabs.com | Building a more connected world. Rev. 1.0 | 38 Si8281/82/83/84 Data Sheet Packaging Symbol Millimeters Min Max aaa -- 0.10 bbb -- 0.33 ccc -- 0.10 ddd -- 0.25 eee -- 0.10 fff -- 0.20 Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing conforms to JEDEC Outline MS-013, Variation AC. 4. Recommended reflow profile per JEDEC J-STD-020C specification for small body, lead-free components. silabs.com | Building a more connected world. Rev. 1.0 | 39 Si8281/82/83/84 Data Sheet Packaging 6.2 Land Pattern: 20-Pin Wide Body SOIC The figure below illustrates the recommended land pattern details for the Si8281/2 in a 20-Pin Wide Body SOIC. The table lists the values for the dimensions shown in the illustration. Figure 6.2. PCB Land Pattern: 20-Pin Wide Body SOIC Table 6.1. 20-Pin Wide Body SOIC Land Pattern Dimensions1, 2 Dimension Feature (mm) C1 Pad Column Spacing 9.40 E Pad Row Pitch 1.27 X1 Pad Width 0.60 Y1 Pad Length 1.90 Note: 1. This Land Pattern Design is based on IPC-7351 design guidelines for Density Level B (Median Land Protrusion). 2. All feature sizes shown are at Maximum Material Condition (MMC), and a card fabrication tolerance of 0.05 mm is assumed. silabs.com | Building a more connected world. Rev. 1.0 | 40 Si8281/82/83/84 Data Sheet Packaging 6.3 Package Outline: 24-Pin Wide Body SOIC The figure below illustrates the package details for the Si8283/4 in a 24-Pin Wide Body SOIC. The table lists the values for the dimensions shown in the illustration. Figure 6.3. 24-Pin Wide Body SOIC Symbol Millimeters Min Max A -- 2.65 A1 0.10 0.30 A2 2.05 -- b 0.31 0.51 c 0.20 0.33 D 15.40 BSC E 10.30 BSC E1 7.50 BSC e 1.27 BSC L 0.40 1.27 h 0.25 0.75 0 8 aaa -- 0.10 bbb -- 0.33 ccc -- 0.10 silabs.com | Building a more connected world. Rev. 1.0 | 41 Si8281/82/83/84 Data Sheet Packaging Symbol Millimeters Min Max ddd -- 0.25 eee -- 0.10 fff -- 0.20 Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing conforms to JEDEC Outline MS-013, Variation AD. 4. Recommended reflow profile per JEDEC J-STD-020 specification for small body, lead-free components. silabs.com | Building a more connected world. Rev. 1.0 | 42 Si8281/82/83/84 Data Sheet Packaging 6.4 Land Pattern: 24-Pin Wide Body SOIC The figure below illustrates the recommended land pattern details for the Si8283/4 in a 24-Pin Wide Body SOIC. The table lists the values for the dimensions shown in the illustration. Figure 6.4. PCB Land Pattern: 24-Pin Wide Body SOIC Table 6.2. 24-Pin Wide Body SOIC Land Pattern Dimensions1, 2 Dimension Feature (mm) C1 Pad Column Spacing 9.40 E Pad Row Pitch 1.27 X1 Pad Width 0.60 Y1 Pad Length 1.90 Note: 1. This Land Pattern Design is based on IPC-7351 design guidelines for Density Level B (Median Land Protrusion). 2. All feature sizes shown are at Maximum Material Condition (MMC), and a card fabrication tolerance of 0.05 mm is assumed. silabs.com | Building a more connected world. Rev. 1.0 | 43 Si8281/82/83/84 Data Sheet Packaging 6.5 Top Marking: 20-Pin and 24-Pin Wide Body SOIC Si828xUV YYWWRTTTTT TW Si828xUV YYWWRTTTTT e4 TW Si8281/82 Top Marking Si8283/84 Top Marking Table 6.3. Si8281/2/3/4 Top Marking Explanation Line 1 Marking: Customer Part Number Si8281, Si8282, Si8283, Si8284 = ISOdriver U = UVLO level: B = 9 V; C = 12 V V = Isolation rating: C = 3.75 kV; D = 5.0 kV Line 2 Marking: RTTTTT = Mfg Code Manufacturing code from the Assembly Purchase Order form "R" indicates revision Line 3 Marking: Circle = 43 mils Diameter "e4" = Pb-Free Symbol Left-justified YY = Year WW = Workweek silabs.com | Building a more connected world. Assigned by the assembly house. Corresponds to the year and workweek of the mold date. Rev. 1.0 | 44 Si8281/82/83/84 Data Sheet Revision History 7. Revision History 7.1 Revision 1.0 March, 2018 * Updated Safety Regulatory Approvals section on page 1, and Tables 4.3, 4.4, and 4.6 to conform with isolation component standard terminology. * Removed references to IEC 60747-5-5 throughout the document and replaced with VDE 0884. * Updated Table 2.2, Recommended Transformers. * Updated Thermal Derating Curve, Figure 4.6. silabs.com | Building a more connected world. Rev. 1.0 | 45 Smart. Connected. Energy-Friendly. Products Quality www.silabs.com/products www.silabs.com/quality Support and Community community.silabs.com Disclaimer Silicon Labs intends to provide customers with the latest, accurate, and in-depth documentation of all peripherals and modules available for system and software implementers using or intending to use the Silicon Labs products. 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