TS3404CD

TS3404 PWM Buck Controller Pin assignment: 1. Out 2. Vcc 3. Comp. 4. FB 5. SCP 6. SS 7. CT 8. Gnd Supply Voltage Range 3.6V to 27V Output Driving Current 200mA Oscillator Frequency up to 300KHz General Description The TS3404 integrates Pulse Width Modulation (PWM) control circuit into a single chip, and makes simple work out of implementing a complete control and protection scheme for a DC-DC step-down converter. The TS3404 provides simple feedback loop compensation, 1.25V reference output, error amplifier, adjustable oscillator, soft start, under voltage lock out (UVLO), short circuit protection(SCP) circuitry, and push pull output circuit. The TS3404 is design for adjustable switching frequency by trimming time capacitor (CT), during low supply voltage situation, the under voltage lock out (UVLO) makes sure that the output are off until the internal circuit operates normally. The TS3404 is offered in DIP-8 and SOP-8 package. Features PWM buck control circuit Operating voltage can be up to 27V Under voltage lock out (UVLO) protection Soft start (SS) circuit Short circuit Protection (SCP) Variable oscillator frequency 300KHz (max) 1.25V voltage reference Output Pin Descriptions Name Output Vcc Comp. FB SCP SS CT Gnd PWM Output Supply Voltage Feedback Loop Compensation Voltage Feedback Short Circuit Protection Soft Start Timing Capacitor Ground Description Applications LCD Monitor xD-ROM, xDSL product DC to DC converters in computers Backlight inverter Ordering Information Part No. TS3404CS TS3404CD Operating Temp. (Ambient) -20 ~ +85 C o Package SOP-8 DIP-8 Absolute Maximum Rating Supply Voltage Amplifier Input Voltage Collector Output Voltage Source Current Sink Current Operating Junction Temperature Range Storage Temperature Range Lead Temperature 1.6mm(1/16”) from case for 10Sec. VCC VI VO ISOURCE ISINK TJ TSTG TLEAD 28 20 Vcc~1.0V 200 200 -20 ~ +150 -65 ~ +150 260 V V V mA mA o o o C C C TS3404 1-5 2003/12 rev. A Recommended Operating Conditions Parameter Supply voltage Amplifier input voltage Collector output voltage Current into feedback terminal Feedback resistor Timing capacitor Oscillator frequency Symbol. VCC VI VO IFB RF CT FOSC Min. 3.6 1.05 Max. 27 1.45 Vcc~1.5 45 Unit V V V uA KΩ 100 100 10 6800 300 pF KHz Electrical Characteristics (VCC =6V, f = 200KHz, Ta =25 oC; unless otherwise specified.) Parameter Reference Comp. Connect to FB Output voltage change with temperature Under voltage lock out (UVLO) Upper threshold Voltage Lower threshold voltage Hysteresis Short circuit protection (SCP) Input threshold voltage Standby voltage Latched input voltage Input (source) current Comparator threshold voltage Oscillator (OSC) Frequency Standard deviation of frequency Frequency change with voltage Error Amplifier Input offset voltage Input offset current Input bias current Common mode input voltage range Open loop voltage amplification Unity gain bandwidth Common mode reject ratio Max. output voltage Min. output voltage Output (sink) current (Comp) Output (source) current (Comp) Symbol Test Conditions Min 1.225 Typ 1.25 - 0.1 - 0.2 2.9 Max 1.275 1 1 Unit V % VREF Ta= -20 C ~ 25 C Ta= 25 C ~ 85 C o o o o VUT VLWT VHT ViT VSTB VLT ISCP VCT FOSC ∆FOSC CT = 270pF CT = 270pF VCC = 3.6V ~ 20V VIO IIO IIB VCM AV GBW CMRR VOH VOL IOI IOO VID = - 0.1V, VO = 1.25V 0.5 - 45 60 VREF~0.1 IO(REF) = 0.1mA, Ta= 25 C o 2.4 0.5 V Ta= 25 C No pull up No pull up VI = 0.7V, Ta= 25 C o o 0.60 100 - 10 0.67 130 50 - 15 1.5 200 10 1 0.75 160 100 - 20 V mV mV uA V KHz % ±6 VO (FB)= 1.25V 160 VCC = 3.6V ~ 20V RF = 200kΩ 1.05 70 80 1.5 80 1 1.6 - 70 ± 100 500 1.45 mV nA nA V dB MHz dB V V mA uA TS3404 2-5 2003/12 rev. A Electrical Characteristics (Continued) (VCC =6V, f = 200KHz, Ta =25 C; unless otherwise specified.) o Parameter Output section Leakage current Sink current Source current Output saturation voltage Short circuit output current PWM comparator Input threshold voltage at f =10KHz (Comp) Total device Average supply current Soft Start Soft start voltage Constant charge current Symbol ILEAK IDRV VSAT ISC VTO VT100 ICCA VSS ISS Test Conditions VO = 25V VIN = 20V VIN= 20V IO = 10mA VO = 6V CT Maximum duty cycle CT = 270pF Min Typ Max 10 Unit uA mA mA 200 200 1.0 120 0.6 1.2 1.3 6 2.3 20 10 0.7 1.5 V mA V mA V uA Functional Block Diagram TS3404 3-5 2003/12 rev. A Typical Application Circuit Device C1 C2 C3 C4 C5 C6 C7 Remark: Value 470uF 10nF 470uF 50nF 270uF 50nF 220nF Device R1 R2 R3 L1 D1 Q1 Value 9K, 1/4W 3K, 1/4W 10K, 1/4W 33uH, 3A SK34A TSM2301CX * Output = 1.25V * (R1/R2 +1) = 1.25V * (9K/3K + 1) = 5V @ 3A * SK34A: Taiwan semiconductor, Schottky 3A/40V in SMA package * TSM2301CX: Taiwan semiconductor, P-Channel MOSFET 4A/20V in SOT-23 package TS3404 4-5 2003/12 rev. A DIP-8 Mechanical Drawing A DIM 8 5 DIP-8 DIMENSION MILLIMETERS MIN 9.07 6.22 3.18 0.35 0.29 3.25 7.75 MAX 0.32 6.48 4.43 0.49 0.31 3.35 8.00 10 o INCHES MIN 0.357 0.245 0.125 0.019 0.011 0.128 0.305 MAX 0.367 0.255 0.135 0.020 0.012 0.132 0.315 10 o A B 1 4 B C D G J K L M 2.54 (typ) 0.100 (typ) L C J K G D M SOP-8 Mechanical Drawing A SOP-8 DIMENSION DIM MILLIMETERS MIN MAX 4.80 3.80 1.35 0.35 5.00 4.00 1.75 0.49 INCHES MIN MAX 0.189 0.150 0.054 0.014 0.196 0.157 0.068 0.019 16 9 B P A B C D F G 1 8 0.40 1.25 1.27 (typ) 0.10 0 5.80 0.25 o 0.016 0.049 0.05 (typ) 0.004 0 0.229 0.010 o G C D K M R K M P R 0.25 7 6.20 0.50 o 0.009 7 0.244 0.019 o F TS3404 5-5 2003/12 rev. A