ZLED7002

ZLED7002
Toggle (Side-Step) Dual-Channel LED Driver
Brief Description
The ZLED7002 toggle (side-step) dual-channel LED
driver is one of our ZLED family of LED control ICs. It
operates in the lower DC voltage supply range of 2.7V to
5.5V. This unique LED driver is capable of controlling a
MAIN channel and a SUB channel. Typically, only one of
the two channels is active and the ZLED7002 toggles
between the channels automatically in response to the
voltage supply level and the related voltage at the UV
(under-voltage protection) pin. A high-to-low transition of
the power supply causes the output current to switch
from the MAIN channel to the SUB channel if the UV pin
voltage (VUV-PIN) is below the ZLED7002’s under-voltage
threshold (VUVTHRSH=1.17V, typical). A low-to-high transition switches the output current from the SUB channel
to the MAIN channel if the UV pin voltage is 80mV (typical) above the under-voltage threshold.
The MAIN channel is a configurable constant current
source driving the MAIN LED string with a maximum
current draw of 250mA. The MAIN LED channel current
is set by an external resistor (R3) connected to the Iset
pin. Alternately, the SUB channel is activated when the
ZLED7002’s SUB pin is pulled to ground. Its current is
determined by the forward voltage of the SUB LED and
external components. The SUB channel can drive up to
100mA current through the LED channel when active.
The ZLED7002 enables voltage-level indicator applications and low-power battery-driven lighting applications
that require switching to a lower-current LED channel
when the supply is low, which extends the lighting lifetime. Because the dropout voltage (VDP) is minimal (as
low as 0.1V when the MAIN channel output current is
~200mA), the ZLED7002 is optimal for battery-powered
applications. Capable of operating efficiently with DC
voltage supplies ranging from 2.7V to 5.5V, it is ideal for
small portable lighting applications.
The ZLED7002 can also reduce bill-of-material costs
because very few external components are required for
most applications, making it an optimal fit for small
devices for which lighting lifetime is critical. Only four
resistors, a diode, and a capacitor are needed for a
typical basic application.
Features
• Automatic MAIN channel short-circuit protection
switches the output current to the SUB channel
if the MAIN LED is shorted
• Under-voltage power supply detection
• Over-temperature protection
Benefits
• Extends lighting life-time by switching to a lowercurrent LED channel when the supply is low
• 80mV (typical) hysteresis prevents unintended
switching activation due to power supply ripple
• Ultra low quiescent current: 250µA typical
• Very few external components needed for operation
Available Support
• Evaluation Kit
Physical Characteristics
• Voltage supply: 2.7V to 5.5V DC
• Operating temperature: -25°C to 85°C
• Small SOP8 package
For additional information on our ZLED driver family,
visit www.zmdi.com/products/led-drivers/
ZLED7002 Typical Application Circuit
© 2011 Zentrum Mikroelektronik Dresden AG — Rev. 3.0
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.
The information furnished in this publication is subject to changes without notice.
ZLED7002
Toggle (Side-Step) Dual-Channel LED Driver
SOP8 Package Dimensions and Pin Assignments
Symbol
Dimension (mm, except θ)
Min
Max
A
1.350
1.750
A1
0.100
0.250
A2
1.450 Typical
Typical Applications
Battery-driven LED lighting including
•
•
•
•
Helmet lighting
Bicycle lighting
Miner lamps
Pocket lights
b
0.350
0.490
c
0.178
0.250
Voltage-level indicators
D
4.800
5.000
General purpose low-voltage industrial and
consumer LED applications
E
3.800
4.000
E1
5.800
6.240
e
1.270 Typical
L
0.400
1.270
θ
0°
8°
Ordering Information
Product Sales Code
Description
ZLED7002-ZI1R
Package
ZLED7002 – Toggle (Side-Step) Dual-Channel LED Driver
SOP8 (Tape & Reel)
ZLED7002KIT-E1
ZLED7002 Evaluation Kit
Kit
Sales and Further Information
www.zmdi.com
Zentrum Mikroelektronik
Dresden AG (ZMD AG)
Zentrum Mikroelektronik
Dresden AG, Japan Office
ZMD America, Inc.
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01109 Dresden
Germany
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USA
Phone +49 (0)351.8822.7.533
Fax
+49 (0)351.8822.8.7533
Phone
Fax
+1 (608) 829-1987
+1 (631) 549-2882
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4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
[email protected]
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation
regarding future manufacture unless otherwise agreed to in writing. The information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer, licensee, or
any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. ZMD AG
hereby expressly disclaims any liability of ZMD AG to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for any damages in
connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or otherwise.
© 2011 Zentrum Mikroelektronik Dresden AG — Rev. 3.0
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.