TC25C25 Datasheet, PDF (4/7 Pages) TelCom Semiconductor, Inc – BICMOS PWM CONTROLLERS

TC25C25
TC35C25
PIN CONFIGURATION (DIP AND SOIC)
IN– ₁
IN+ 2
SYNC 3
OSC OUT 4
CT 5
RT 6
DISCHARGE 7
SOFT START 8
TC25C25EPE
TC35C25CPE
16 VREF
15 V+IN
14 OUTPUT B
13 VDD
12 GND
11 OUTPUT A
10 SHDN
9 CMPTR
BICMOS PWM CONTROLLERS
IN– 1
IN+ 2
SYNC 3
OSC OUT 4
CT 5
RT 6
DISCHARGE 7
SOFT START 8
TC25C25EOE
TC35C25COE
16 VREF
15 V+IN
14 OUTPUT B
13 VDD
12 GND
11 OUTPUT A
10 SHDN
9 CMPTR
PIN DESCRIPTION
Pin No.
1
2
3
Symbol
IN^–
IN⁺
SYNC
4
OSC OUT
5
C_T
6
R_T
7
DISCHARGE
8
SOFT START
9
CMPTR
10
SHDN
11
OUTPUT A
12
GND
13
V_DD
14
OUTPUT B
15
V^+IN
16
V_REF
Description
Error Amplifier inverting input for output voltage reference input and amplifier gain set.
Error Amplifier, non-inverting input for output voltage feedback to regulate voltage.
Input pin for PWM controller oscillator synchronization of two or more controllers from an
external clock output or from another PWM controller oscillator output.
Pin for output of the internal oscillator. This signal can be used as a master oscillator to
sync other oscillators to run at the same timing period.
Pin is the capacitor timing input to set oscillator frequency in conjunction with pin 6 R_T timing
resistor.
Pin for timing resistor input to set oscillator frequency by setting the charge current into
capacitor C_T of pin 5.
Pin for discharging the timing capacitor, C_T of pin 5. During discharging time period, PWM
controller output is disabled. This is called dead time. With a resistor between pin 7 and pin 5,
the dead time can be controlled.
Pin for soft starting the power supply. A capacitor from this pin to GND pin 12 will limit
duty cycle till capacitor is charged above error amplifier output.
Pin for compensation of the feedback loop response.
Pin for terminating both outputs of pins 11 and 14. This will shutdown the power supply
outputs. A positive input with shutdown threshold of 2.4V is required for shutdown.
Pin for output drive of phase A to drive push pull transistor A.
Pin for ground return for all inputs and output signals.
Pin for power supply input to operate the output drivers A and B.
Pin for output drive of phase B to drive push pull transistor B.
Pin for voltage bias supply input for all PWM controller functions except output drive circuits.
Pin is the reference supply output voltage of 4.0 volts that may be used for any voltage
reference purposes such as a reference to control output voltage.
4-114
TELCOM SEMICONDUCTOR, INC.