AS3525-A/-B C22O22
Data Sheet, Confidential
7.4.2
3V Step-Up Converter
7.4.2.1 General
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Output voltage 3V to 3.6V (BVDD) programmable in 4 steps via DCDC3p bit to save power
Input voltage 1V (1.2V) to 3V, voltages higher than that can be connected to BVDD directly
Maximum output current to BVDD: 150mA
Current mode operation
On-chip compensation and feedback network
On chip 300mΩ NMOS switch
PWM mode with 1.2MHz switching frequency
Inductor current limitation 850mA
Pulse skipping capability
Low quiescent current: 40μA in PFM-mode, 300μA in PWM mode
≤1μA shutdown current
uses external coil (6.8μH) and Schottky diode (500mA)
Figure 45 DCDC 3V Block Diagram
7.4.2.2 Parameter
Table 99 DCDC Boost Parameter
Symbol
Parameter
Supply Current
Notes
Power down mode
Min
Typ
Max Unit
IVDD2.9
5
μA
μA
μA
V
PFM mode operation
40
PWM mode (low output load)
RLoad>220Ω
300
VSTARTUP Startup Voltage
1.0
VHOLD
RSW_on
fSW
Hold-on Voltage
IOUT=1mA, VBAT falling from 1.5 to 0V
0.5
V
Internal Switch RDS_ON
Switching Frequency
300
500
mΩ
kHz
MHz
ns
Start-up, X3VOK=1
100
250
1.2
100
100
85
PWM mode operation, X3VOK=0
tON_min
tOFF_min
ηeff
Minimum On-time
Minimum Off-time
Efficiency
ns
IOUT=20mA, Vin=1.35
IOUT=50mA, Vin=1.5
1.0V ≤ VB1V ≤ 3.0V
VB1V=1.0V
%
87
%
ISW_LIM
IOUT
Current Limit
Load Current
0.60
0.85
1.10
150
A
mA
Vin=1.0..2.0V, C(VBAT_1V) = 2.2μF ceramic || 2000μF Elko, C(BVDD) = 3 x 2.2μF ceramic, L=DS1608 6.8μH, Temp = 25deg
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