ABSOLUTE MAXIMUM RATINGS
V
CC
-0.3V to +10V
DRIVE -0.3V to V
CC
+ 0.3V
EOR -0.3V to V
CC
+ 0.3V
STDN -0.3V to The lower of (+5.0V) or (V
CC
+ 0.3V)
SENSE -0.3V to The lower of (+5.0V) or (V
CC
+ 0.3V)
Operating Temp. -40°C to +85°C
Storage Temp. -55°C to +125°C
Power Dissipation 450mW
ZXSC400
ISSUE 1 - JANUARY 2003
2
Symbol Parameter Conditions Limits Units
Min Typ Max
Supply parameters
V
IN
V
CC
Range 1.8 8 V
Iq
1
Quiescent Current V
CC
= 8V 220 A
I
STDN
Shutdown Current 4.5 A
Eff
1
Efficiency 30mA > I
LED
> 10mA 80 %
Acc
REF
Reference tolerance 1.8V < V
CC
< 8V -3.0 3.0 %
TCO
REF
Reference Temp Co 0.005 %/⬚C
T
DRIVE
Discharge pulse width 1.8V < V
CC
<8V 1.7 s
F
OSC
Operating Frequency 200 kHz
Input parameters
V
SENSE
Sense voltage 22 28 34 mV
I
SENSE
Sense input current V
FB
=0V,V
SENSE
= 0V -1 -7 -15 A
V
FB
Feedback voltage 291 300 309 mV
I
FB
2
Feedback input current V
FB
=0V,V
SENSE
= 0V -1.2 -4.5 A
V
IH
Shutdown high voltage 1.5 V
CC
V
V
IL
Shutdown low voltage 0 0.55 V
dV
LN
Line voltage regulation 0.5 %/V
Output parameters
I
OUT
3
Output current Vin > 2V, Vout = 10.5V 50 mA
I
DRIVE
Transistor drive current Vdrive = 0.7V 2 3.5 5 mA
V
DRIVE
Transistor voltage drive 1.8V < V
CC
<8V 0 V
CC
-0.4 V
C
DRIVE
Mosfet gate drive cpbty 300 pF
dILD
4
Load current regulation 0.1 mA/V
ELECTRICAL CHARACTERISTICS
Test Conditions V
CC
= 3V, T= -40°C to 85°C unless otherwise stated.
Note
1
Excluding gate/base drive current.
2
I
FB
is typically half these values at 300mV.
3
System not device spec, including recommended transistors. 10.5V represents 3 white LEDs.
4
Change in LED current with changing supply voltage (LED V
F
x number of series LEDs).
