AAT1171
600mA Voltage-Scaling Step-Down Converter
for RF Power Amplifiers with Bypass Switch
Typical Characteristics
DAC to Bypass Transient Response
(LL Mode; VIN = 4.2V; RL = 10Ω; COUT = 4.7µF; L = 2.2µH)
Enable Soft Start
(VIN = 3.6V; VOUT = 1.8V; RL = 4.5Ω;
COUT = 4.7µF; L = 2.2µH)
4.2V
VOUT
1V/div
1.8V
VOUT
1V/div
0
Enable
2V/div
0.6V
0
0
1.3V
VDAC
0.5V/div
IIN
200mA/div
0.2V
0
0
Time (25µs/div)
Time (50µs/div)
Load Transient Response
(VIN = 4.2V; VOUT = 3.3V; COUT = 4.7µF; L = 2.2µH)
Load Transient Response
(VIN = 3.6V; VOUT = 1.8V; COUT = 4.7µF; L = 2.2µH)
VOUT
(AC coupled)
20mV/div
VOUT
(AC coupled)
20mV/div
3.51V
1.914V
3.26V
1.798V
500mA
525mA
IOUT
200mA/div
IOUT
100mA/div
250mA
200mA
Time (20µs/div)
Time (20µs/div)
Line Transient Response
(VOUT = 1.5V; RL = 10ΩΩ; COUT = 4.7µF; L = 2.2µH)
VIN
0.5V/div
3.6V
3.0V
1.56V
VOUT
(AC coupled)
50mV/div
1.44V
Time (50µs/div)
1171.2006.06.1.0
11
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
