UC3842T STMICROELECTRONICS [STMicroelectronics], UC3842T Datasheet - Page 2

• Manufacturer Part Number: UC3842T
• Description: HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

UC3842T - UC3843T - UC3844T - UC3845T
ABSOLUTE MAXIMUM RATINGS
* All voltages are with respect to pin 5, all currents are positive into the specified terminal.
PIN CONNECTION (top view)
PIN FUNCTIONS
ORDERING NUMBERS
2/15
Symbol
No
1
2
3
4
5
6
7
8
T
P
P
E
T
V
V
I
O
stg
tot
tot
O
L
i
i
GROUND
Function
OUTPUT
COMP
I
R
SENSE
V
V
V
T
Supply Voltage (low impedance source)
Supply Voltage (Ii < 30mA)
Output Current
Output Energy (capacitive load)
Analog Inputs (pins 2, 3)
Error Amplifier Output Sink Current
Power Dissipation at T
Power Dissipation at Tamb
Storage Temperature Range
Lead Temperature (soldering 10s)
CC
/C
FB
ref
T
This pin is the Error Amplifier output and is made available for loop compensation.
This is the inverting input of the Error Amplifier. It is normally connected to the switching
power supply output through a resistor divider.
A voltage proportional to inductor current is connected to this input. The PWM uses this
information to terminate the output switch conduction.
The oscillator frequency and maximum Output duty cycle are programmed by connecting
resistor R
This pin is the combined control circuitry and power ground.
This output directly drives the gate of a power MOSFET. Peak currents up to 1A are sourced
and sunk by this pin.
This pin is the positive supply of the control IC.
This is the reference output. It provides charging current for capacitor C
UC3842TD
UC3843TD
UC3844TD
UC3845TD
SO8
T
to Vref and cpacitor C
COMP
I
R
SENSE
amb
T
V
/C
FB
Parameter
T
25 C (Minidip)
25 C (SO8)
1
2
3
4
Minidip/SO8
D95IN332
T
to ground. Operation to 500kHz is possible.
8
7
6
5
Description
V
Vi
OUTPUT
GROUND
REF
UC3842TN
UC3843TN
UC3844TN
UC3845TN
Minidip
Self Limiting
– 0.3 to 5.5
– 65 to 150
Value
1.25
800
300
30
10
5
1
T
through resistor R
Unit
mW
mA
W
V
A
V
C
C
J
T
.