Zxld1321, Electrical characteristics – Diodes ZXLD1321 User Manual
Page 5
ZXLD1321
Issue 1 - January 2008
5
www.zetex.com
© Zetex Semiconductors plc 2008
Electrical characteristics (
Test conditions: VIN = 3V, T
AMB
= 25
°
C unless otherwise stated
(a)
)
DC-DC converter supply parameters
NOTES:
(a) Production testing of the device is performed at 25
°
C. Functional operation of the device and parameters specified from -40
°
C to
+125
°
C are guaranteed by design, characterisation and process control.
(b) Between 1.2V and 2.2V the device will run in the Low Voltage Startup Mode (for details refer to section "Low Voltage Operation")
DC-DC converter input parameters
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
IN
Supply voltage
Normal operation
2.0
12
V
V
IN
(Start)
Supply voltage for start-up
(b)
Start-up mode
1.2
2.4
V
V
UV-
Under-voltage detection threshold
Normal operation to start-up mode
VIN falling
1.8
V
V
UV+
Under-voltage detection threshold
Start-up mode to normal operation
VIN rising
2.2
V
Iq
Quiescent current
Measured into VIN
ADJ pin floating.
(Excluding switch
base current).
1.5
mA
I
STBY
Standby current
Measured into VIN.
ADJ pin grounded
12
20
µA
V
REF
Internal reference voltage
ADJ pin floating
2.0V<VIN<18V
480
500
520
mV
TCO
(REF)
Internal reference temperature
coefficient.
50
ppm
/K
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
SENSE
Peak switch current sense
voltage
Measured on ISENSE
pin CFB pin at 0V
45
55
65
mV
V
SENSE
(SU)
Peak switch current sense
voltage in start-up mode
Measured on ISENSE
pin.
Start-up mode
VIN=1.2V
10.5
mV
I
SENSE
Sense input current
Measured into
ISENSE
with pin at
0V. CFB pin at 0V
-15
-7
-1
µA
C
FB
Control loop compensation
capacitor
10
nF
V
ADJ
External dc control voltage
applied to ADJ pin to adjust
output current
DC brightness
control mode
50
500
mV
V
ADJ(th)
Switching threshold of ADJ
pin
Standby state to
normal operation
26
28
30
mV
TCO
(VADJ)
Temperature coefficient of
VADJ(th)
+0.3
%/K
R
ADJ
Internal resistor between
VREF and ADJ
VADJ<500mV
100
k
Ω
VADJ(clmp) Clamp voltage on ADJ pin
100µA injected into
ADJ pin
575
mV