Diodes ZXLD1360 - Manual (Page 2)

ZXLD1360
ZXLD1360
Document number: DS33471 Rev. 4 - 2
2 of 25
www.diodes.com
March 2011
© Diodes Incorporated
A Product Line of
Diodes Incorporated
Block Diagram
Voltage
regulator
Low voltage
detector
``
L1
D1
LX I
SENSE
V
IN
R
S
5 4 1
R1
0.2V
R2
R3
1.35V
R5
20k
R4
200k
D1
1.25V
ADJ
3
GND
2
C1
4.7µF
5V
V
IN
MN
Figure 1. Block diagram – With Pin Connections
Pin Descriptions
Name Pin No. Description
LX 1 Drain of NDMOS switch
GND 2 Ground (0V)
ADJ 3
Multi-function On/Off and brightness control pin:
• Leave floating for normal operation.(V
ADJ
= V
REF
= 1.25V giving nominal average output current
o I
OUTnom
= 0.1/R
S
)
• Drive to voltage below 0.2V to turn off output current
• Drive with DC voltage (0.3V < V
ADJ
< 2.5V) to adjust output current from 25% to 200% of
I
OUTnom
• Drive with PWM signal from open-collector or open-drain transistor, to adjust output current.
• Adjustment range 25% to 100% of I
OUTnom
for f>10kHz and 1% to 100% of I
OUTnom
for f <
500Hz
• Connect a capacitor from this pin to ground to increase soft-start time.
(Default soft-start time = 500µs. Additional soft-start time is approximately 500µs/nF)
I
SENSE
4
Connect resistor R
S
from this to V
IN
to define nominal average output current I
OUTnom
=0.1/R
S
(Note: R
SMIN
=0.1V with ADJ pin open circuit)
V
IN
5
Input voltage (7V to 30V). Decouple to ground with 4.7µF of higher X7R ceramic capacitor close to
device