Diodes ZXLD1352 - Manual (Page 4)

ZXLD1352
ZXLD1352
Document number: DS33469 Rev. 3 - 2
4 of 21
www.diodes.com
December 2010
© Diodes Incorporated
A Product Line of
Diodes Incorporated
Electrical Characteristics
(Test conditions: V
IN
= 12V, T
amb
= 25°C, unless otherwise specified.)
Symbol Parameter Conditions Min. Typ. Max. Unit
V
SU
Internal regulator start-up threshold V
IN
rising 4.8 V
I
INQoff
Quiescent supply current
with output off
ADJ pin grounded 20 30 µA
I
INQon
Quiescent supply current
with output switching ADJ pin floating
f = 250kHz
250 500 µA
V
SENSE
Mean current sense threshold voltage
(defines LED current setting accuracy) Measured on I
SENSE
pin with respect
to V
IN
V
ADJ
=1.25V
95 100 105 mV
V
SENSEHYS
Sense threshold hysteresis ±15 %
I
SENSE
I
SENSE
pin input current V
SENSE
= V
IN
-0.1 1.25 10 µA
V
REF
Internal reference voltage Measured on ADJ pin with pin floating 1.21 1.25 1.29 V
ΔV
REF
/
ΔT Temperature coefficient of V
REF
50 ppm/°C
V
ADJ
External control voltage range on ADJ
pin for dc brightness control
1
0.3 2.5 V
V
ADJoff
DC voltage on ADJ pin to switch device
from active (on) state to quiescent (off)
state
V
ADJ
falling 0.15 0.2 0.25 V
V
ADJon
DC voltage on ADJ pin to switch device
from quiescent (off) state to active (on)
state
V
ADJ
rising 0.2 0.25 0.3 V
R
ADJ
Resistance between ADJ pin and V
REF
35 65 k Ω
I
LXmean
Continuous LX switch current 0.37 A
R
LX
LX Switch ‘On’ resistance 1.5 2 Ω
I
LX(leak)
LX switch leakage current 1 µA
D
PWM(LF)
Duty cycle range of PWM signal
applied to ADJ pin during PWM
dimming mode PWM frequency 100Hz – 1kHz
PWM amplitude = V
REF
Measured on ADJ pin
0.001 1
Brightness control range 1000:1
f
LX
Operating frequency
(See graphs for more detail)
ADJ pin floating
L=100µH (0.82V)
I
OUT
=350mA @ V
LED
=3.4V
Driving 1 LED
250 kHz
t
PD
Internal comparator propagation delay 50 ns
Notes: 1. Production testing of the device is performed at 25°C. Functional operation of the device and parameters specified over a -40°C to +105°C temperature
range, are guaranteed by design, characterization and process control.
2. 100% brightness corresponds to VADJ = VADJ(nom) = VREF. Driving the ADJ pin above V
REF
will increase the VSENSE threshold and output current
proportionally.