Unitrode UCC29421
The UCC39421 family of synchronous RESET PWM controllers is optimized to operate 1 from dual alkaline/NiCd cells or a single Lithium-Ion (Li-Ion) cell, and convert to LOWBAT adjustable output voltages from 2.5 V to 10 8 V. For applications where the input voltage does not exceed the output, a standard boost configuration is used.| Part No. | UCC29421 |
|---|---|
| Datasheet | UCC29421 Download |
| Manufacturer |  Unitrode |
| Description | Multimode High Frequency PWM Controller |
| Buy | Stock & Price |
APPLICATIONS
D Up to 2-MHz Oscillator D Synchronizable Fixed Frequency Operation D High-Efficiency Low-Power Mode D High-Efficiency at Very Low-Power with Programmable Variable Frequency Mode D Pulse-by-Pulse Current Limit D 5-µA Supply Current in Shutdown D 150-µA Supply Current in Sleep Mode D Selectable NMOS or PMOS Rectification D Built-In Power-On Reset (UCC39422 Only) D Built-In Low-Voltage Detect (UCC39422 Only) description SYNC/SD 13 RT 14 1.8 V(MIN) 1.24 V VREF PWM OSC VPUMP 7 VIN 9 CHARGE PUMP VPUMP 8 CP 3 VOUT 2 RSEN RECT 4 ANTI− CROSS COND. VGD RSEL 19 CHRG 6 PWM CIRCUITRY CURRENT LIMIT LOW POWER MODE SLOPE COMPENSATION PFM MODE CONTROL GND 15 + X10 ERROR 1.24 V AMP + ISENSE 12 PGND 5 FB 17 COMP 18 PFM 16 + + 2 CELL ALKALINE/ + NiCd OR 1 LI−ION VOUT 50 mV TYP 200 mS RESET/ POR 1.22V UCC39422 ONLY + + 1.18 V RSADJ 20 VDET 11 1.24 V UDG−98122 For other applications where the input voltage can swing above and below the output, a 1:1 coupled inductor (Flyback or SEPIC) is used in place of the single inductor.
