ZLED7002 Datasheet, PDF (1/12 Pages) List of Unclassifed Manufacturers – Toggle (Side-Step) Dual-Channel LED Driver

Toggle (Side-Step) Dual-Channel
LED Driver
ZLED7002
Datasheet
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 tran-
sition switches the output current from the SUB channel
to the MAIN channel if the UV pin voltage is 80mV (typi-
cal) 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 applica-
tions 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 life-
time. 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 lower-
current 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
ZLED7002 Typical Application Circuit
2.7 to 5.5 V
+
DC
R1
-
ZLED7002
D1
VCC
SUB
UV
MAIN
Iset
GND
C1 R2 R3 ^NC
NC
R4
SUB
LED
MAIN
LED
SW1
© 2016 Integrated Device Technology, Inc.
1
April 20, 2016