AP2003 Synchronous PWM Controller Features General Description - Single or Dual Supply Application - 0.8V + 1.0% Voltage Reference. - Fast transient response. - Synchronous operation for high efficiency (95%) - Soft Start functions - Small size with minimum external components - Industrial temperature range - Under Voltage Lockout function - SOP-8L package Applications - Microprocessor core supply - Low cost synchronous applications - Voltage Regulator Modules (VRM) - DDR termination supplies - Networking power supplies - Sequenced power supplies Pin Assignment (Top View) SS/SHDN VCC DRVH GND (Preliminary) 1 8 COMP 2 AP2003 7 SENSE 3 6 BSTH 4 5 DRVL SOP-8L Ordering Information The AP2003 is a low-cost, full featured, and synchronous voltage-mode controller designed for use in single ended power supply applications where efficiency is of the primary concern. This synchronous operation allows the elimination of heat sinks in many applications. The AP2003 is ideal for implementing DC/DC converters needed to power advanced microprocessors in low cost systems, or in distributed power applications where efficiency is important. Internal level-shift, high-side drive circuitry, and preset shoot-thru control, allows the use of inexpensive N-channel power switches. AP2003 features include temperature compensated voltage reference, an internal 200KHz virtual frequency oscillator, under-voltage lockout protection, soft-start, and shutdown function. Pin Descriptions Name VCC Description Chip supply voltage DRVH High side driver output DRVL Low side driver output BSTH Bootstrap, high side driver SENSE Voltage sense input COMP Compensation pin AP2003 X X Package S: SOP-8L Packing SS/ SHDN Blank : Tube A : Taping GND Soft start, a capacitor to ground sets the slow start time Ground This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev. 0.0 Jun.5, 2003 1/7 AP2003 Synchronous PWM Controller (Preliminary) Block Diagram VCC Vbg Under Voltage 0.8V + - Oscillator One-Shot COMP PWM Error Amp SENSE + - DRVH BSTH DRVH Vcc 10uA Cross Current Control S 0.5V + - R Ob SS/SHDN GND 0.6V DRVL DRVL Foult 2uA + - Absolute Maximum Ratings Symbol Parameter Max. VIN JC VCC to GND Thermal Resistance Junction to Case JA Thermal Resistance Junction to Ambient TOP Operating Temperature Range TST TLEAD Storage Temperature Range Lead Temperature (Soldering) 10 Sec. Anachip Corp. www.anachip.com.tw -1 to 14 60 160 Unit V C/W o o C/W -40 to +85 o -65 to +150 o 300 o C C C Rev. 0.0 2/7 Jun.5, 2003 AP2003 Synchronous PWM Controller (Preliminary) Electrical Characteristics Unless specified: VCC = 12V; GND = 0V; FB = VO; VBSTH-GND = 12V; TJ = 25oC Symbol Parameter Conditions Min. VCC 4.2 Typ. Max. Unit 16 V 10 mA Power Supply VCC Supply Voltage ICC Supply Current VLINE Line Regulation 6 VO = 2.5V 0.5 % dB Error Amplifier AOL Gain (AOL) 50 IB Input Bias 5 8 uA 220 KHz Oscillator FOSC DCMAX Oscillator Frequency 180 200 Oscillator Max Duty Cycle 90 95 % Mofset Drivers IDRVH DRVH Source/Sink IDRVL DRVL Source/Sink VBSTH - VDRVH =4.5V VDRVH - VPHASE = 2V VBSTH - VDRVL = 4.5V VDRVL - VGND = 2V 1 A 1 A Protection TDEAD Dead Time 45 100 nS 0.808 V +1 % Reference VREF Reference Voltage Accuracy 0oC to 70oC 0.792 0.8 -1 Soft Start ISSC Charge Current ISSD Discharge Current Under voltage lockout (UVLO) Upper threshold voltage VUT (VCC) Lower threshold voltage VLWT (VCC) VHT Hysteresis (VCC) VSS = 1.5V 8.0 10 12 uA VSS = 1.5V 1.3 2 2.7 uA IO(REF) = 0.1mA TA = 25C 4.2 V 4.1 V 200 mV Note 1. Specification refers to Typical Application Circuit. Note 2. This device is ESD sensitive. Use of standard ESD handling precautions is required. Anachip Corp. www.anachip.com.tw Rev. 0.0 3/7 Jun.5, 2003 AP2003 Synchronous PWM Controller (Preliminary) Typical Application Circuit (1) + C6 C7 C8 680/6.3V 680/6.3V 680/6.3V Vin 5V - C2 0.1u C5 10u 1 SS/SHDN COMP 8 2 VCC SENSE 7 3 DRVH BSTH 6 4 GND DRVL 5 R8 191* R7 127 +12V R5 Option Q1 STP40NE R6 Option Q2 STP40NE AP2003 L1 4uH + D1 Option C9 180/4V C10 180/4V C11 180/4V C12 180/4V C13 180/4V Vout=2.0V* - Note: * Vout=0.8 x (1+R8/R7) (2) + C6 C7 C8 680/6.3V 680/6.3V 680/6.3V Vin 5V - D2 C2 0.1u C5 10u 1 SS/SHDN COMP 8 2 VCC SENSE 7 3 DRVH BSTH 6 4 GND DRVL 5 C1 1u R8 191* R7 127 R5 Option Q1 STP40NE R6 Option Q2 STP40NE AP2003 L1 4uH + D1 Option C9 180/4V C10 180/4V C11 180/4V C12 180/4V C13 180/4V Vout=2.0V* - 5V input with Bootstrapped BSTH Note: * Vout=0.8 x (1+R8/R7) Anachip Corp. www.anachip.com.tw Rev. 0.0 4/7 Jun.5, 2003 AP2003 Synchronous PWM Controller Function (Preliminary) Description error Synchronous Buck Converter Primary VCORE power is provided by a synchronous, voltage-mode pulse width modulated (PWM) controller. This section has all the features required to build a high efficiency synchronous buck converter, shutdown function. The output voltage of the synchronous converter is set and controlled by the output of the error amplifier. The external resistive divider reference voltage is derived from an internal trimmed band-gap voltage reference. The inverting input of the error amplifier receives its voltage from the SENSE pin. amplifiers are clamped to a voltage proportional to the voltage on SS/ SHDN . This limits the on-time of the high-side MOSFETs, thus leading to a controlled ramp-up of the output voltages. Hiccup Mode During power up, the SS/ SHDN pin is internally pulled low until VCC reaches the under-voltage lockout level of 4.2V. Once VCC has reached 4.2V, the SS/ SHDN pin is released and begins to source 10uA of current to the external soft-start capacitor. As the soft-start voltage rises, the output of the internal error amplifier is clamped to this voltage. When the error signal reaches the level of the internal triangular oscillator, which swings from 1V to 2V at a fixed frequency of 200KHz, switching occurs. As the error signal crosses over the oscillator signal, the duty cycle of the PWM signal continues to increase until the output comes into regulation. The internal oscillator uses an on-chip capacitor and trimmed precision current sources to set the oscillation frequency to 200KHz. The triangular output of the oscillator sets the reference voltage at the inverting input of the comparator. When the oscillator output voltage drops below the error amplifier output voltage, the comparator output goes high. This pulls DRVL low, turning off the low-side FET, and DRVH is pulled high, turning on the high-side FET (once the cross-current control allows it). When the oscillator voltage rises back above the error amplifier output voltage, the comparator output goes low. This pulls DRVH low, turning off the high-side FET, and DRVL is pulled high, turning on the low-side FET (once the cross-current control allows it). As SENSE increases, the output voltage of the error amplifier decreases. This causes a reduction in the on-time of the high-side MOSFET connected to DRVH, hence lowering the output voltage. The soft-start voltage will begin to decrease as the 2uA of current discharge the external capacitor. When the soft-start voltage reaches 0.8V, the SS/ SHDN pin will begin to source 10uA and begin to charge the external capacitor causing the soft-start voltage to rise again. Again, when the soft-start voltage reaches the level of the internal oscillator, switching will occur. In conclusion, above is shown a typical "12V Application Circuit" which has a BSTH voltage derived by bootstrapping input voltage to the PHASE node through diode D2. This circuit is very useful in cases where only single input power of 5V(or 12V) is available. Under Voltage Lockout The under voltage lockout circuit of the AP2003 assures that the high-side MOSFET driver outputs remain in the off state whenever the supply voltage drops below set parameters. Lockout occurs if VCC falls below 4.1V. Normal operation resumes once VCC rises above 4.2V. In order to prevent substrate glitching, a small-signal diode should be placed in close proximity to the chip with cathode connected to PHASE and anode connected to GND. Soft Start Initially, SS/ SHDN sources 10uA of current to charge an external capacitor. The outputs of the Anachip Corp. www.anachip.com.tw Rev. 0.0 5/7 Jun.5, 2003 AP2003 Synchronous PWM Controller (Preliminary) Marking Information 5 8 (Top View) Logo Part No. ID code: internal Xth week: 01~52 4 1 AC AP2003 YY WW ~ Year: "01" =2001 "02" =2002 SOP-8L ~ Anachip Corp. www.anachip.com.tw Rev. 0.0 6/7 Jun.5, 2003 AP2003 Synchronous PWM Controller (Preliminary) Package Information E H Package Type: SOP-8L L VIEW "A" D 0.015x45 7 (4X) C A A2 7 (4X) B VIEW "A" A1 e y Symbol Dimensions In Millimeters Dimensions In Inches Min. Nom. Max. Min. Nom. Max. A 1.40 1.60 1.75 0.0550 0.063 0.069 A1 0.10 - 0.25 0.0400 - 0.100 A2 1.30 1.45 1.50 0.0510 0.057 0.059 B 0.33 0.41 0.51 0.0130 0.016 0.020 C 0.19 0.20 0.25 0.0075 0.008 0.010 D 4.95 5.05 5.30 0.1890 0.191 0.199 E 3.70 3.9 4.10 0.1500 0.154 0.157 e - 1.27 - - 0.050 - H 5.79 5.99 6.20 0.2280 0.236 0.244 L 0.25 0.71 1.27 0.0150 0.028 0.050 y - - 0.10 - - 0.004 - 8O 0 O - 8 Anachip Corp. www.anachip.com.tw O 0 O Rev. 0.0 7/7 Jun.5, 2003