Supertex inc.
does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.”
Supertex inc.
does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the
Supertex inc.
(website: http//www.supertex.com)
©2011
Supertex inc.
All rights reserved. Unauthorized use or reproduction is prohibited.
Supertex inc.
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com
4
AN-H64
081109
Feature
HV9910B
HV9961
Fixed-Frequency Mode
Resistor from RT to GND
N/A
Fixed Off-Time Mode
Resistor from RT to GATE
Resistor from RT to GND
(value adjustment needed for
conversion from HV9910B)
Current Threshold
250mV or V
LD
(peak)
272mV or V
LD
/5.5 (average)
Current Threshold Accuracy
10%
Auto-zero
LED Current Accuracy
Depends on inductance and
switching frequency variation
Independent of inductance and
switching frequency variation
LED Current Regulation
Poor. LED current depends on input
and output voltage
Good
LD Input Range
0 to 250mV
0.2V(0.15V) to 1.5V
Residual LED Current at V
LD
= GND
5% (typ.) of I
LED
@ V
LD
= 250mV
0A
Current Limit Threshold
none
440mV
Hiccup Time
N/A
400µs
Minimum On-Time
465ns
1000ns
Maximum Duty Cycle
0.5 (fixed freq.), 0.8 (fixed T
OFF
)
0.75
Table 1. Functional comparison of HV9910B and HV9961.