HV9901
Functional Block Diagram and Typical Application
Notes: 1. This diode and bridge rectifier required only for AC operation.
2. For non-isolated AC operation the entire circuit must be floating.
3. All comparators have open drain outputs.
1N4148
See Note 1.
VDD
VIN
1
16
15
14
4.7µF
UVLO
100nF
C
A
1.25 V
VREF
Bandgap
Reference
R
HDa
100nF
R
LED
2R
HOLD/DELAY
CHD
R
HDb
10K
VDD
GT
FB
S
4
13
12
11
10
9
VN2460N8
R
FBb
VDD
Q
R
FBa
100ns
Delay
R
R
100nF
CS
1.25V
5.5kΩ
5
6
7
8
C
VCC
ENI
5 V
Low Limit
High Limit
C
µP
RS
VDD
COM
VDD
Oscillator
shut down
40µA
SYNC
ENO
High Duty
Cycle
Oscillator
Rosc
RT
POL
06/26/02rev.4
1235 Bordeaux Drive, Sunnyvale, CA 94089
TEL: (408) 744-0100 • FAX: (408) 222-4895
www.supertex.com
©2002 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
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