CS3865C Datasheet, PDF (4/8 Pages) Cherry Semiconductor Corporation – High Performance Dual Channel Current Mode Controller with ENABLE

PACKAGE PIN #
16 L PDIP & SO Wide
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Package Pin Description
PIN SYMBOL
FUNCTION
SYNC
C_T
R_T
V_FB1
COMP₁
Sense₁
V_OUT1
Gnd
Pwr Gnd
V_OUT2
Sense₂
COMP₂
V_FB2
ENABLE₂
V_REF
V_CC
A positive going pulse applied to this input will synchronize the
oscillator. A DC voltage within the range of 2.4V to 5.5V will inhibit
the oscillator.
Timing capacitor C_T connects pin to ground setting oscillator fre-
quency.
Resistor R_T connects to ground setting the charge current for C_T. Its
value must be between 4.0k and 16k.
The inverting input of error amplifier 1. Normally it is connected to
the switching power supply output.
The output of error amplifier 1, for loop compensation.
Output 1 pulse by pulse current limit.
Drives the power switch at output 1.
Logic ground
Power ground. Power device return is connected to this pin.
Drives the power switch at output 2.
Output 2 pulse by pulse current limit.
Output of error amplifier 2, for loop compensation.
Inverting input of error amplifier 2. Normally it is connected to the
switching power supply output.
Output 2 disable. A logic low at this pin disables V_OUT2.
5.0V reference output. It can source current in excess of 30mA.
The positive supply of the IC.
Typical Performance Characteristics
Timing Resistor vs. Oscillator Frequency
16
14
12
10
8.0
V_CC=
6.0 ^15V
4.0 ^TA=25°C
10k
30k 50k
100k
300k 500k
f _OSC OSCILLATOR FREQUENCY (Hz)
1.0M
Max. Output Duty Cycle vs. Oscillator Frequency
50
48
46
OUT 2
44
OUT 1
42 V_CC = 15V
R_T = 4.0kΩ to 16kΩ
40 ^CL ^{= 15pF}
T_A = 25°C
38
10k
30k 50k 100k
300k 500k 1.0M
f _OSC OSCILLATOR FREQUENCY (Hz)
Error Amp Open-Loop Gain & Phase vs. Frequency
100
80
GAIN
60
0
V_CC = 15V
V_O = 1.5V TO 2.5V 30
R_L = 100kΩ
T_A = 25°C
60
40
PHASE ⁹⁰
20
120
0
150
-20
10k
100k
1.0k 10k 100k
f, FREQUENCY (Hz)
1.0M
180
10M
4
Current Sense Input Threshold
vs. Error Amp Output Voltage
0.6
V_CC = 15V
0.5
0.4
T_A = 125°C
T_A = 25°C
0.3
0.2
T_A = -55°C
0.1
0
0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
ERROR AMP OUTPUT VOLTAGE (V)