s-8813 Seiko Instruments Inc., s-8813 Datasheet - Page 23

• Manufacturer Part Number: s-8813
• Description: 3-channel White Led Driver Ic Charge Pump Ic With Built-in Constant-current Circuit
• Manufacturer: Seiko Instruments Inc.

1. Efficiency
*1. “Efficiency” in the electrical characteristics means the efficiency of the charge pump circuit block. The ideal efficiency is
Rev.2.1
The ideal efficiency including the constant current circuit is expressed as following expression.
indicated by the following expression.
Major Load Characteristics Examples
100
80
60
40
20
Efficiency =[ V
Efficiency =[ (V
0
3-CHANNEL WHITE LED DRIVER IC (CHARGE PUMP IC WITH BUILT-IN CONSTANT-CURRENT CIRCUIT)
_00
*1
1
( η ) vs. Stabilized Output Current (I
V
V
V
IN
IN
IN
=2.7 V
=3.0 V
=4.5 V
CPOUT
IOUT1
×I
× (I
I
OUT
OUT1
10
OUT1
[mA]
) +(V
+I
OUT2
IOUT2
+I
OUT
×I
Ta=25°C
OUT3
) Characteristics
OUT2
) ] / [ 2.0 × V
) +(V
100
Seiko Instruments Inc.
IOUT3
×I
IN
OUT3
2.
×(I
OUT1
) ] / [ 2.0 ×V
CPOUT Pin Voltage (V
(I
OUT
+I
) Characteristics
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
OUT2
0
+I
IN
OUT3
×(I
10
OUT1
) ]
20
+I
CPOUT
OUT2
) vs. Stabilized Output Current
30
I
+I
OUT
OUT3
V
[mA]
40
IN
) ]
=3.0 V. Ta=25°C
S-8813 Series
50
60
70
23