S-8821 Series www.sii-ic.com VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER Rev.5.0_00 (c) Seiko Instruments Inc., 2002-2010 The S-8821 series is a CMOS step-up charge pump DC-DC converter with a voltage regulation function. The S-8821 series consists of an oscillation circuit, a controller, a reference voltage circuit, an error amplifier circuit, and an output switching transistor, and can regulate the output voltage by PFM control. Since small ceramic capacitors can be used for the pump capacitor, input capacitor, and output capacitor, the mounting area can be minimized. Features * Step-up PFM control CMOS charge pump * Power supply voltage: * Output voltage: * Output voltage accuracy: * Built-in soft start circuit: * Output current * Oscillation frequency: * ON/OFF function: * Lead-free, Sn 100%, halogen-free*1 1.6 to 5.0 V 2.5 to 5.5 V, selectable in 0.1 V steps. 2 % max. 1.0 ms typ. 25 mA (VIN=(VOUT(S) x 0.80) V) 1.0 MHz typ. During standby: 1 A max. *1. Refer to " Product Name Structure" for details. Applications * Lithium ion battery driven applications * Local power supply * Power supply for white LED display backlights Packages * SOT-23-6W * SNT-8A Seiko Instruments Inc. 1 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 Block Diagram VIN CIN=4.7 F VOUT SW1 COUT=10 F Rs C+ SW2 PFM control oscillator circuit (1.0 MHz) Switch control circuit CPUMP=0.10 F C- Rf - SW3 Soft start circuit ON/OFF circuit SW4 ON/OFF Figure 1 2 + Seiko Instruments Inc. Reference voltage GND VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 Product Name Structure * The output voltage and packages for the S-8821 Series can be selected at the user's request. Refer to the "Product name" for the meanings of the characters in the product name, "Package" regarding the package drawings and "Product name list" for the full product names. 1. Product name (1) SOT-23-6W S-8821 xx A MH - xxx TF x Environmental code S: Lead-free, halogen-free G: Lead-free (for details, please contact our sales office) IC direction in tape specifications*1 Product name (abbreviation)*2 Package name (abbreviation) MH: SOT-23-6W Output voltage 25 to 55 (E.g., when the output voltage is 2.5 V, it is expressed as 25.) *1. Refer to the tape specifications at the end of this book. *2. Refer to the product name list. (2) SNT-8A S-8821 xx A PH - xxx TF U Environmental code U: Lead-free (Sn 100%), halogen-free IC direction in tape specifications*1 Product name (abbreviation)*2 Package name (abbreviation) PH: SNT-8A Output voltage 25 to 55 (E.g., when the output voltage is 2.5 V, it is expressed as 25.) *1. Refer to the tape specifications at the end of this book. *2. Refer to the product name list. 2. Package Package Name SOT-23-6W SNT-8A Drawing Code Package Tape Reel MP006-B-P-SD PH008-A-P-SD MP006-B-C-SD PH008-A-C-SD MP006-B-R-SD PH008-A-R-SD Seiko Instruments Inc. Land PH008-A-L-SD 3 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 3. Product name list Table 1 Output Voltage SOT-23-6W SNT-8A 2.5 V S-882125AMH-M2ATFz S-882125APH-M2ATFU 3.0 V S-882130AMH-M2FTFz 3.3 V S-882133AMH-M2ITFz 3.5 V S-882135AMH-M2KTFz 3.6 V S-882136AMH-M2LTFz 4.0 V S-882140AMH-M2PTFz 4.5 V S-882145AMH-M2UTFz 5.0 V S-882150AMH-M2ZTFz S-882150APH-M2ZTFU 5.2 V S-882152AMH-M3BTFz 5.5 V S-882155AMH-M3ETFz Remark 1. Contact the SII sales department for products with an output voltage other than those specified above. 2. z: G or S 3. Please select products of environmental code = U for Sn 100%, halogen-free products. 4 Seiko Instruments Inc. VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 Pin Configurations Table 2 SOT-23-6W Top view 6 1 5 2 Pin No. 1 4 3 Symbol VIN 2 C+ 3 C- 4 ON/OFF 5 6 GND VOUT Pin Description Voltage input pin Charge-pump pump capacitor connection pin (positive pin) Charge-pump pump capacitor connection pin (negative pin) Shutdown pin High level (H) : normal operation (step-up) Low level (L) : step-up halt (all circuit halt) GND pin Voltage output pin Figure 2 SNT-8A Top view Table 3 1 8 2 7 3 6 4 5 Figure 3 Pin No. Symbol Pin Description Charge-pump pump capacitor connection pin 1 C+ (positive pin) 2 VIN Voltage input pin 3 NC*1 No connection 4 VOUT Voltage output pin Shutdown pin 5 ON/OFF High level (H) : normal operation (step-up) Low level (L) : step-up halt (all circuit halt) 6 GND GND pin 7 NC*1 No connection Charge-pump pump capacitor connection pin 8 C- (negative pin) *1. The NC pin is electrically open. The NC pin can be connected to VIN or GND. Seiko Instruments Inc. 5 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 Absolute Maximum Ratings Table 4 Items C+ pin voltage C- pin voltage VIN pin voltage VOUT pin voltage ON/OFF pin voltage Power dissipation Symbols VC+ VC- VIN VOUT VON/OFF SOT-23-6W (Ta=25C unless otherwise specified) Absolute Maximum Ratings Units V VGND-0.3 to VGND+7.5 V VGND-0.3 to VGND+7 V VGND-0.3 to VGND+5.5 V VGND-0.3 to VGND+7 V VGND-0.3 to VIN+0.3 300 (When not mounted on board) mW 650*1 mW 450*1 mW -40 to +85 C -40 to +125 C PD SNT-8A Operating ambient temperature Topr Storage temperature Tstg *1. When mounted on board [Mounted board] (1) Board size: 114.3 mm x 76.2 mm x t1.6 mm (2) Board name: JEDEC STANDARD51-7 Caution The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. (2) When not mounted on board 400 Power Dissipation PD (mW) Power Dissipation PD (mW) (1) When mounted on board 800 700 600 SOT-23-6W 500 400 300 SNT-8A 200 100 0 0 50 100 150 350 300 250 200 150 100 50 0 0 Ambient Temperature Ta (C) 50 Seiko Instruments Inc. 150 Ambient Temperature Ta (C) Figure 4 Power Dissipation of Package 6 100 Rev.5.0_00 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Electrical Characteristics Table 5 (VIN=(VOUT(S) x 0.60) V*1, Ta=25C unless otherwise specified) Items Symbols Conditions VOUT(S) 2.9 V Operation input voltage VIN Output voltage*2 VOUT(E) VOUT(S) > 2.9 V IOUT=10 mA VIN=(VOUT(S) x 0.54) V VIN=(VOUT(S) x 0.60) V*1 VIN=(VOUT(S) x 0.80) V VIN=(VOUT(S) x 0.60) V*1 to (VOUT(S) - 0.10) V, IOUT=10 mA IOUT=0.1 mA to 10 mA IOUT=10 mA VOUT=(VOUT(S) x 0.60) V, Measure waveform at C- pin VIN=(VOUT(S) x 0.54) V, VOUT(S) 3.0 V, IOUT=5 mA VIN=VOUT(S), VOUT=(VOUT(S) + 0.5) V VIN=(VOUT(S) x 0.54) V*6 to 5.0 V, VON/OFF=0 V *6 Output current*3 IOUT Line regulation VOUT1 Load regulation Ripple voltage*4 Maximum oscillation frequency VOUT2 VRIP Efficiency*5 fosc Min. Typ. Max. 1.6 5.0 VOUT(S) x 5.0 0.54 VOUT(S) x VOUT(S) x VOUT(S) 0.98 1.02 5 15 25 Units Test circuits V 2 V 2 V 2 mA mA mA 2 2 2 50 100 mV 2 40 70 80 mV mVp-p 2 2 800 1000 1200 kHz 2 90 % 1 Operation consumption ISS1 35 60 A current Standby consumption ISSS 0.3 1.0 A current ON/OFF pin input VSH VIN=(VOUT(S) x 0.54) V*6 to 5.0 V 1.5 V voltage (high level) ON/OFF pin input VSL VIN=(VOUT(S) x 0.54) V*6 to 5.0 V 0.3 V voltage (low level) ON/OFF pin input ISH VIN=(VOUT(S) x 0.54) V*6 to 5.0 V -0.1 0.1 A current (high level) ON/OFF pin input ISL VIN=(VOUT(S) x 0.54) V*6 to 5.0 V -0.1 0.1 A current (low level) Soft start time tSS IOUT=10 mA 0.2 1.0 4.0 ms *1. In case of VOUT 3.3 V, VIN=2.0 V *2. VOUT(E): Actual output voltage VOUT(S): Specified output voltage *3. The output current at which the output voltage becomes 97 % of VOUT(E) after gradually increasing the output current. *4. Design assurance *5. The ideal efficiency is indicated by the following expression. Efficiency ()=(VOUT x IOUT) / (2.0 x VIN x IOUT) *6. In case of VOUT 2.9 V, VIN=1.6 V Seiko Instruments Inc. 2 1 1 1 1 1 1 7 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Test Circuits 1. 4.7 F A A VIN VOUT C+ GND C- ON/OFF A A A Figure 5 2. 0.1 F 4.7 F VIN VOUT C+ GND C- ON/OFF A A 10 F Figure 6 8 Seiko Instruments Inc. Rev.5.0_00 Rev.5.0_00 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Operation 1. Basic operation Figure 7 shows the block diagram of the S-8821 Series. The S-8821 series controls the output voltage by using the pulse frequency modulation (PFM) method. The SW1 to SW4 switching transistors are switched ON/OFF with the clock generated by the internal oscillator circuit, and operates the step-up charge pump. The output voltage is fed back and the voltage split by feedback resistances Rs and Rf and reference voltage (Vref) are compared by a comparator. This comparator signal is used to modulate the oscillation pulse frequency in order to keep the output voltage constant. VIN CIN=4.7 F VOUT SW1 COUT=10 F Rs C+ SW2 PFM control oscillator circuit (1.0 MHz) Switch control circuit CPUMP=0.10 F C- + Rf - SW3 SW4 Soft start circuit ON/OFF circuit ON/OFF Reference voltage GND Figure 7 Seiko Instruments Inc. 9 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 2. Step-up Charge Pump The step-up charge pump steps up the voltage by switching ON/OFF of the SW1 to SW4 switching transistors. First, in order to charge the pump capacitance (CPUMP), set SW1 to OFF, SW2 to ON, SW3 to OFF, and SW4 to ON (charge cycle). Following charging the electricity, in order to discharge the charged electricity to the output capacitance (COUT), SW1 set the switches as to ON, SW2 to OFF, SW3 to ON, and SW4 to OFF (discharge cycle). The input voltage can be stepped up to a constant voltage value by repeating this charge cycle and discharge cycle. Figure 8 shows the charge cycle, and Figure 9 shows the discharge cycle. SW 2: ON V IN SW 1: OFF C PUMP 0.10 F C OUT 10 F Current flow SW 4: ON SW 3: OFF Figure 8 SW 2: OFF V IN SW 1: ON C PUMP 0.10 F C OUT 10 F Current flow SW 4: OFF SW 3: ON Figure 9 10 Seiko Instruments Inc. Rev.5.0_00 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series 3. Shutdown Pin (ON/OFF Pin) Setting the ON/OFF pin to the Low level ("L") causes the voltage of the VOUT pin to change to the GND level and simultaneously the operation of all the internal circuit to stop. At this time, the consumption current is largely reduced, to a level of approximately 0.3 A. The structure of the ON/OFF pin is as shown in Figure 10. Since the ON/OFF pin is neither pulled down nor pulled up internally, do not use it in the floating state. When the ON/OFF pin is not used, connect it to the VIN pin. Table 6 ON/OFF pin "H": Power on "L": Power off Internal circuit Operating Stop VIN VOUT pin voltage Set value VGND level VIN ON/OFF GND Figure 10 4. Soft Start Function The S-8821 Series features a built-in soft start circuit. Upon power application or when the ON/OFF pin is switched from "L" to "H", the output voltage gradually rises over the soft start time, and the output current is gradually output as a result. This soft start function reduces the input current rush. Seiko Instruments Inc. 11 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 External Capacitor Selection 1. Input and Output Capacitors (CIN, COUT) The input capacitor (CIN) lowers the power supply impedance and averages the input current. The CIN value is selected according to the impedance of the power supply that is used. Select a ceramic capacitor with a small equivalent series resistance (ESR). Although this figure varies according to the impedance of the power supply that is used as well as the load current value, it is generally in the range of 4.7 F to 10 F. For the output capacitor (COUT), select a ceramic capacitor with a small ESR for smoothing the ripple voltage. A value of 10 F is recommended for the capacitance value. Use of a capacitor with a capacitance lower than 10 F results in a larger ripple voltage. Conversely, use of a capacitor with a capacitance greater than 10 F results in the output voltage not being able to rise up to setting value and the impossibility to obtain the desired output current. 2. Pump Capacitor (CPUMP) The pump capacitor (CPUMP) is required for stepping up the voltage. Select a ceramic capacitor with a small ESR. A capacitance value of 0.10 F is recommended. Use of a capacitor with a capacitance greater than 0.10 F results in a larger ripple voltage. Conversely, use of a capacitor with a capacitance lower than 0.10 F results in the output voltage not being able to raise up to setting value and the impossibility to obtain the desired output current. 12 Seiko Instruments Inc. Rev.5.0_00 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Precautions * Regarding the wiring to the VIN pin, VOUT pin, C+ pin, C- pin and GND pin, be careful to perform pattern wiring so as to obtain low impedance. * Always connect a capacitor to the VOUT pin, C+ pin, and C- pin. * Connect CIN and COUT in the vicinity of the IC and sufficiently strengthen the wiring for GND pin and VIN pin in order to lower the impedance of the wiring resistance, etc. High impedance may cause unstable operation. Moreover, in selecting CIN and COUT, perform a full evaluation of the actual usage conditions. * Connect CPUMP in the vicinity of the IC and sufficiently strengthen the wiring for the C+ pin and C- pin in order to lower the impedance of the wiring resistance, etc. High impedance may cause instable operation. Moreover, in selecting CPUMP, perform a full evaluation of the actual usage conditions. * The ON/OFF pin is configured as shown in Figure 9 and is neither pulled up or down internally, so do not use this pin in a floating state. When not using the ON/OFF pin, connect it to the VIN pin. Moreover, please do not apply voltage higher than VIN + 0.3 V to an ON/OFF pin. Current flows for a VIN pin through the protection diode inside IC. * Since this IC consists of double step-up circuits, it cannot set more than twice voltage of VIN to VOUT(S). * Be careful about the usage conditions for the input/output voltages and output current to make sure that dissipation within the IC does not exceed the allowable power dissipation of the package. For reference, the calculation of the power consumption in this IC is shown below. PD=(VIN x 2.0 - VOUT) x (IOUT) Reference: VIN=4.2 V, VOUT=5.5 V, IOUT=10 mA PD=(4.2 x 2.0 - 5.5) x 0.010=29 mW * Since the information described herein is subject to change without notice, confirm that this is the latest one before using. * Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in electrostatic protection circuit. * SII claims no responsibility for any and all disputes arising out of or in connection with any infringement of the products including this IC upon patents owned by a third party. Seiko Instruments Inc. 13 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 Characteristics (Typical Data) (1) Output voltage vs. Operation input voltage S-882133A S-882150A IOUT=10 mA, Ta=25C IOUT=10 mA, Ta=25C 5.30 3.50 3.45 5.20 5.10 3.35 VOUT [V] VOUT [V] 3.40 3.30 3.25 3.20 5.00 4.90 4.80 3.15 3.10 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 4.70 1.5 2.0 5.5 2.5 3.0 VIN [V] 3.5 4.0 4.5 5.0 5.5 VIN [V] (2) Output voltage vs. Output current S-882133A S-882150A VIN=2.0 V, Ta=25C VIN=3.0 V, Ta=25C 5.30 5.20 3.40 3.35 5.10 VOUT [V] VOUT [V] 3.50 3.45 3.30 3.25 5.00 4.90 3.20 4.80 3.15 3.10 0 5 15 10 20 25 4.70 30 0 5 15 10 IOUT [mA] 25 20 30 IOUT [mA] (3) Operation consumption vs. Operation input voltage S-882133A S-882150A Ta=25C 50 45 50 45 40 35 35 40 ISS1 [A] ISS1 [A] Ta=25C 30 25 20 30 25 20 15 15 10 1.5 10 1.5 2.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VIN [V] 14 2.5 3.0 3.5 VIN [V] Seiko Instruments Inc. 4.0 4.5 5.0 5.5 Rev.5.0_00 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series (4) Ripple voltage vs. Operation input voltage S-882133A S-882150A IOUT=10 mA, Ta=25C 100 100 80 80 VRIP [mVp-p] VRIP [mVp-p] IOUT=10 mA, Ta=25C 60 40 40 20 20 0 1.5 2.0 60 2.5 3.0 4.0 3.5 4.5 5.0 0 1.5 2.0 5.5 2.5 3.0 VIN [V] 3.5 4.0 4.5 5.0 5.5 VIN [V] (5) Efficiency*1 vs. Operation input voltage S-882133A S-882150A IOUT=10 mA, Ta=25C 100 100 80 80 [%] [%] IOUT=10 mA, Ta=25C 60 40 40 20 1.5 2.0 60 2.5 3.0 3.5 4.0 4.5 5.0 20 1.5 2.0 5.5 2.5 3.0 VIN [V] 3.5 4.0 4.5 5.0 5.5 VIN [V] *1. The ideal efficiency is indicated by the following expression. Efficiency ()=(VOUT x IOUT) / (2.0 x VIN x IOUT) (6) Maximum oscillation frequency vs. Operation input voltage S-882133A S-882150A Ta=25C 1300 1200 1200 1100 1100 fOSC [kHz] fOSC [kHz] Ta=25C 1300 1000 900 900 800 800 700 1.5 2.0 1000 2.5 3.0 3.5 4.0 4.5 5.0 5.5 700 1.5 2.0 VIN [V] 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VIN [V] Seiko Instruments Inc. 15 VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER S-8821 Series Rev.5.0_00 (7) Load fluctuation S-882133A S-882150A VIN=2.0 V CH1 VIN=3.0 V CH1 10 mA 10 mA CH2 CH2 1 mA 1 mA [1 ms/div.] [1 ms/div.] CH1: VOUT [20 mV/div.] CH2: IOUT [2 mA/div.] CH1: VOUT [20 mV/div.] CH2: IOUT [2 mA/div.] (8) Input voltage fluctuation S-882133A S-882150A IOUT=10 mA CH1 IOUT=10 mA CH1 5.0 V 3.3 V CH2 CH2 3.0 V 1.8 V [1 ms/div.] CH1: VOUT [20 mV/div.] CH2: VIN [1 V/div.] 16 Seiko Instruments Inc. [1 ms/div.] CH1: VOUT [20 mV/div.] CH2: VIN [1 V/div.] 2.90.2 1.90.2 6 0.95 5 1 4 2 3 +0.1 0.15 -0.08 0.95 +0.1 0.4 -0.05 No. MP006-B-P-SD-1.0 TITLE SOT236-B-PKG Dimensions No. MP006-B-P-SD-1.0 SCALE UNIT mm Seiko Instruments Inc. 4.00.1(10 pitches:40.00.2) +0.1 o1.5 -0 2.00.05 +0.2 o1.0 -0 0.250.1 4.00.1 1.40.2 3.20.2 3 2 1 4 5 6 Feed direction No. MP006-B-C-SD-1.0 TITLE SOT236-B-Carrier Tape No. MP006-B-C-SD-1.0 SCALE UNIT mm Seiko Instruments Inc. 12.5max. 9.00.3 Enlarged drawing in the central part o130.2 (60) (60) No. MP006-B-R-SD-1.0 SOT236-B-Reel TITLE MP006-B-R-SD-1.0 No. SCALE UNIT QTY mm Seiko Instruments Inc. 3,000 1.970.03 8 7 6 5 3 4 +0.05 1 0.5 2 0.08 -0.02 0.480.02 0.20.05 No. PH008-A-P-SD-2.0 TITLE SNT-8A-A-PKG Dimensions PH008-A-P-SD-2.0 No. SCALE UNIT mm Seiko Instruments Inc. +0.1 o1.5 -0 5 2.250.05 4.00.1 2.00.05 o0.50.1 0.250.05 0.650.05 4.00.1 4 321 5 6 78 Feed direction No. PH008-A-C-SD-1.0 TITLE SNT-8A-A-Carrier Tape PH008-A-C-SD-1.0 No. SCALE UNIT mm Seiko Instruments Inc. 12.5max. 9.00.3 Enlarged drawing in the central part o130.2 (60) (60) No. PH008-A-R-SD-1.0 TITLE SNT-8A-A-Reel No. PH008-A-R-SD-1.0 SCALE UNIT QTY. mm Seiko Instruments Inc. 5,000 0.52 2.01 0.52 0.3 0.2 0.3 0.2 0.3 0.2 0.3 Caution Making the wire pattern under the package is possible. However, note that the package may be upraised due to the thickness made by the silk screen printing and of a solder resist on the pattern because this package does not have the standoff. No. PH008-A-L-SD-3.0 TITLE SNT-8A-A-Land Recommendation PH008-A-L-SD-3.0 No. SCALE UNIT mm Seiko Instruments Inc. www.sii-ic.com * * * * * * * The information described herein is subject to change without notice. Seiko Instruments Inc. is not responsible for any problems caused by circuits or diagrams described herein whose related industrial properties, patents, or other rights belong to third parties. The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. When the products described herein are regulated products subject to the Wassenaar Arrangement or other agreements, they may not be exported without authorization from the appropriate governmental authority. Use of the information described herein for other purposes and/or reproduction or copying without the express permission of Seiko Instruments Inc. is strictly prohibited. The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Seiko Instruments Inc. The products described herein are not designed to be radiation-proof. Although Seiko Instruments Inc. exerts the greatest possible effort to ensure high quality and reliability, the failure or malfunction of semiconductor products may occur. The user of these products should therefore give thorough consideration to safety design, including redundancy, fire-prevention measures, and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue.