Preliminary YB1314
120mA 1x/1.5x/2x Charge Pump for White LED
Description
The YB1314 charge pump drive up to 4
white LEDs with regulated constant current.
The devices can be used to produce
current levels up to 30mA for each output
from a 2.7V to 5.5V input. The 1MHz
fix-frequency switching allows for tiny
external components, and the regulation
scheme is optimized to ensure low EMI and
low input ripple.
Serial data input control is used to enable,
disable and set the LED drive current for a
32 level logarithmic scale LED brightness
control. Internal softstart circuitry effectively
reduces the in-rush current. YB1314 also
provides
short
circuit
protection,
over-temperature
protect-
tion
and
over-voltage protection. In shutdown mode,
the shutdown current is less than 1碌A(chǔ).
YB1314 is available in a QFN-16 3*3
package.
Features
Input Range : 2.7V to 5.5V
Drives up to 4 LEDs at 30mA Each
1MHz Internal Oscillator
Thermal Protection Shutdown
Output Short-circuit Current Limit and
Overvoltage Protection
Undervoltage Lockout With
Hysteresis
Automatic Soft-Start Reduces
In-Rush Current
Three Charge Pump Mode錛?x/1.5x/2x
3mm x 3mm QFN package
Applications
White LED Backlighting
Handheld PCs and PDAs
Mobile Phone
Typical Application Circuit
VIN
VOUT
C1+
C1-
C2+
C1
1碌F
V
BATTERY
+
-
C
IN
1碌F
C
OUT
2.2碌F
YB1314
C2-
D1
D2
D3
C2
1碌F
EN/SET
EN/SET
GND
D4
D4
D3
D2
D1
Figure 1. Typical application circuit
YB1314 MRev.0.1
www.yobon.com.tw
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