AK7903 Datasheet, PDF (6/10 Pages) Asahi Kasei Microsystems – DCDC Step-down Converter for NiH2 Battery

[AK7903]
ANALOG CHARACTERISTICS
(Ta=25℃, VIN=5.0V, VDD=3.0V, GND=0V( Note 3))
Symbol
Parameter
Condition
Min
Typ
Vin
Iddsdn
Treg
Ilimt
Vsense
Ipre1
Ipre2
Ipre3
fosc
Tstart
Effi
DCDC CONVERTER、FIXED CURRENT CIRCUIT
Input Voltage
In the case of VIN=3.8V,
VOUT= 1.8V is guaranteed
4.1
(3.8V)
Shut-down Current EN=L
2
Stop Temperature
120
Current Limit
Vin=5.0V
1000
Current Detection
Accuracy
R=0.47Ω,Iout=300mA
-5
R=0.353Ω, ISET= “Low”
Output Current1 Vin=4.1 ～ 5.5V,Vout=0.2 ～
400
3.5V
R=0.470Ω, ISET= “Low”
Output Current 2 Vin=4.1 ～ 5.5V,Vout=0.2 ～
300
3.5V
R=0.470Ω, ISET= “High”
Output Current 3 Vin=4.1 ～ 5.5V,Vout=0.2 ～
80
3.5V
Switching Frequency Freq= 1220kHz
-2
The time which from EN＝
Start-up Time
“L→H” to the time which
20
charge current is 90% of the
setting current.
Efficiency (Note 4) Vout=1.8V、Iout=300mA
80
Max
Unit
5.5
V
10
uA
℃
mA
5
％
mA
mA
mA
+2
%
ms
％
OP-AMP
VDD
Input Voltage
2.8
Maximum Output Load≧10kΩ（＠1/2*VDD） 0.05
Gain1
Gain 1
PIN1→OPOUT
Gain2
Gain 2
PIN2→OPOUT
Opout1
Output Level 1 PIN1= 1.75V
Opout2
Output Level 2 PIN2= 3.5V
IDD1 Power consumption 1 EN2= “H”, 無負荷
IDD2 Power consumption 2 EN2= “L”, 無負荷
Load_Cap Maximum Load CAP
Vil
Vih
Vimax
Ibias1
Ibias
Low Level Input
High Level Input
Maximum Input
Input Bias Current 1
Input Bias Current 2
DIGITAL INPUT/OUTPUT
Input Pins
Input Pins
1.2
EN2, CONT pins
EN1 pin =VIN
Input Pins
Note 3. All the characteristic is supposed that recommend external parts is used.
Note 4. Exclude SENSE resistor consumption.
3.2
V
VDD-0.05 V
3.75
倍
1.96
倍
1.95
V
2.26
V
1.7
4
mA
0.1
2
µA
50
pF
0.4
V
V
VDD+0.3
V
5
µA
1
uA
MS1190-E-00
6
2010/6