S-8813 Datasheet, PDF (23/29 Pages) Seiko Instruments Inc – 3-CHANNEL WHITE LED DRIVER IC (CHARGE PUMP IC WITH BUILT-IN CONSTANT-CURRENT CIRCUIT)

3-CHANNEL WHITE LED DRIVER IC (CHARGE PUMP IC WITH BUILT-IN CONSTANT-CURRENT CIRCUIT)
Rev.2.1_00
S-8813 Series
 Major Load Characteristics Examples
1. Efficiency^*1 (η) vs. Stabilized Output Current (I_OUT) Characteristics 2. CPOUT Pin Voltage (V_CPOUT) vs. Stabilized Output Current
(I_OUT) Characteristics
100
VIN=2.7 V
80
60 ^{VIN=3.0 V}
40 _{VIN=4.5 V}
20
0
1
10
Ta=25°C
100
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
0
VIN=3.0 V. Ta=25°C
10 20 30 40 50 60 70
IOUT [mA]
IOUT [mA]
*1. “Efficiency” in the electrical characteristics means the efficiency of the charge pump circuit block. The ideal efficiency is
indicated by the following expression.
Efficiency =[ V_CPOUT × (I_OUT1 +I_OUT2 +I_OUT3) ] / [ 2.0 × V_IN ×(I_OUT1 +I_OUT2 +I_OUT3) ]
The ideal efficiency including the constant current circuit is expressed as following expression.
Efficiency =[ (V_IOUT1 ×I_OUT1) +(V_IOUT2 ×I_OUT2) +(V_IOUT3 ×I_OUT3) ] / [ 2.0 ×V_IN ×(I_OUT1 +I_OUT2 +I_OUT3) ]
Seiko Instruments Inc.
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