Electrical Characteristics: -25≤TA≤85˚C for CS2844/2845, 0≤TA≤70˚C for CS3844/3845. VCC=15V (Note 1); RT=10kΩ,
CT=3.3nF for sawtooth mode., unless otherwise stated.
CS2844/CS2845
CS3844/CS3845
PARAMETER
TEST CONDITIONS
MIN TYP MAX MIN TYP MAX UNITS
ꢀ Total Standby Current
Start-Up Current
0.5
11
34
1.0
17
0.5
11
34
1.0 mA
Operating Supply Current
VCC Zener Voltage
VFB=VSense=0V RT=10kΩ, CT=3.3nF
17
mA
V
ICC=25mA
ꢀ PWM Section
Maximum Duty Cycle
Minimum Duty Cycle
46
48
50
0
46
48
50
0
%
%
CS2844
CS3844
CS2845/CS3845
PARAMETER
TEST CONDITIONS
MIN
TYP MAX MIN TYP MAX MIN TYP MAX UNITS
ꢀ Under-Voltage Lockout Section
Start Threshold
15
9
16
10
17
11
14.5
8.5
16
10
17.5
11.5
7.8
7.0
8.4
7.6
9.0
8.2
V
V
Min. Operating After Turn On
Voltage
Notes:
1. Adjust Vcc above the start threshold before setting at 15V.
3. Parameter measured at trip point of latch with VFB=0.
4. Gain defined as:
2.These parameters, although guaranteed, are not 100% tested in production.
∆VCOMP
A =
; 0 ≤ VSense ≤ 0.8V.
∆VSense
Package Pin Description
PACKAGE PIN #
14L
PIN SYMBOL
FUNCTION
8L
16L
PDIP/SO SO Narrow SO Wide
1
2
3
4
1
3
5
7
3
4
5
6
COMP
VFB
Error amp output, used to compensate error amplifier.
Error amp inverting input.
Sense
OSC
Noninverting input to Current Sense Comparator.
Oscillator timing network with Capacitor to Ground, resis-
tor to VREF
.
5
6
9
8
11
Gnd
Pwr Gnd
VOUT
Ground.
10
Output driver Ground.
Output drive pin.
10
12
11
13
14
V
CCPwr
VCC
Output driver positive supply.
Positive power supply.
Output of 5V internal reference.
No Connection.
7
8
12
14
15
VREF
NC
2,4,6,13
1,2,7,8,9,16
3
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
