AZ494AP-E1 Datasheet – Pulse-Width-Modulation Control

Part Number: AZ494AP-E1

Function: PULSE-WIDTH-MODULATION CONTROL CIRCUITS

Package: SOIC 16, DIP 16 Type

Manufacturer: BCD Semiconductor

Image and Pinouts:

AZ494AP-E1 datasheet

 

Description

The AZ494AP-E1 is a voltage mode pulse width modulation switching regulator control circuit designed primarily for power supply control.

The AZ494A, AZ494C consists of a reference voltage circuit, two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, and an output control circuit. The precision of voltage reference (V REF) is improved up to ± 1% through trimming and this provides a better output voltage regulation. The AZ494A/C provides for push pull or single-ended output operation, which can be selected through the output control.

Block Diagram:

AZ494AP-E1 Datasheet

 

Pulse width modulation (PWM) is a technique used in electronic circuits to control the amount of power delivered to a load without dissipating excess energy as heat. PWM works by varying the duty cycle of a pulse train, which is a series of pulses that alternate between a high state and a low state.

Features

1. Stable 4.95V/5V Reference Voltage Trimmed to ±1.0% Accuracy
2. Uncommitted Output TR for 200mA Sink or Source Current
3. Single-End or Push-Pull Operation Selected by Output Control
4. Internal Circuitry Prohibits Double Pulse at Either Output
5. Complete PWM Control Circuit with Variable Duty Cycle
6. On-Chip Oscillator with Master or Slave Operation

Applications:

1. SMPS
2. Back Light Inverter
3. Charger

 

AZ494AP-E1 Datasheet PDF Download
AZ494AP-E1 pdf

Other data sheets are available within the file:  AZ494AM, AZ494AM-E1, AZ494AMTR, AZ494AMTR-E1, AZ494AP

SD6834 Datasheet PDF – PWM+PFM CONTROLLER – Silan

Part Number: SD6834

Function: CURRENT MODE PWM+PFM CONTROLLER WITH BUILT-IN HIGH VOLTAGE MOSFET

Package: DIP 8 Pin Type

Manufacturer: Silan Microelectronics

Image and Pinouts:
SD6834 datasheet pinout

Description

The SD6834 is built for high-voltage MOSFET switching power supply external sense resistor. The current mode PWM + PFM controller family. The circuit is low standby power consumption, low starting current. SD6834 is current mode PWM+PFM controller with built-in high-voltage MOSFET used for SMPS. It features low standby power and low start current. In standby mode, the circuit enters burst mode to reduce the standby power dissipation. The switch frequency is 25~67KHz decided by the load with jitter frequency for low EMI.

Built-in peak current compensation circuit makes the limit peak current stable even with different input AC voltage. Maximum peak current compensation during power-on reduces pressure on transformer to avoid saturation, the peak current compensation will decrease for balance after power-on. Limit output current can be adjusted through the resistor connected to CS. It integrates various protections such as undervoltage lockout, overvoltage protection, overload protection, leading edge blanking, primary winding overcurrent protection and thermal shutdown. The circuit will restart until normal if protection occurs.

Block Diagram :

SD6834 Block Diagram

The SD6834 is used for off-line switching power supply integrated circuits. Gate driver circuit includes high-voltage power circuit MOSFET, optimized and current mode Type PWM + PFM controller. The controller includes a frequency oscillator and various protection functions. Frequency jitter oscillator circuit can be reduced EMI. Maximum peak current compensation circuit reduces the stress starts transformer. CS terminal resistance can be adjusted by the limit peak current. In the light load When the circuit hiccup mode can effectively lower standby power consumption. Protection features include: undervoltage lockout, overvoltage protection, overload protection Care, primary coil overcurrent protection and thermal protection. The leading edge blanking function of the circuit, the MOSFET has opened to ensure the shortest possible time, eliminating the The interference caused by erroneous MOSFET off.

Features

1. Various switching frequency following load for the high efficiency

2. EMI Frequency jitter for low EMI

3. Overvoltage, primary winding overcurrent, overload and over temperature protections

4. External peak current sense resistor

5. Undervoltage lockout

6. Built-in high voltage MOSFET

SD6834 Datasheet PDF Download

SD6834 pdf