AAT1171 Datasheet, PDF (2/22 Pages) Advanced Analogic Technologies – 600mA Voltage-Scaling Step-Down Converter for RF Power Amplifiers with Bypass Switch

DATA SHEET
AAT1171
600mA Voltage-Scaling Step-Down Converter
for RF Power Amplifiers with Bypass Switch
Pin Descriptions
Pin #
TDFN33-12
1
WLCSP-12
N/A
2, 3
5, 9
4
7
5
6
6
1
7
2
8
3
9
4
10
12
11
8, 11
12
10
EP
N/A
Symbol
N/C
VOUT
VCC
AGND
DAC
EN
BYPASS
MODE/SYNC
VIN
PGND
LX
Function
Not connected.
Feedback input pin. This pin is connected to the converter output. It is used to
complete the control loop, regulating the output voltage to the desired value.
When in bypass mode, a low resistance MOSFET is connected between this pin
and VIN.
Bias supply. Supply power for the internal circuitry. Connect to input power via
low pass filter with decoupling to AGND.
Analog ground. Connect the return of all small signal components to this pin.
Control voltage input from a DAC. Input voltage between 0.2V and 1.2V to con-
trol output voltage of the converter. Force pin to 1.3V for bypass switch enable.
Enable DC/DC converter, active high.
Enable control to bypass the DC/DC converter when PA transmitting at full
power from low battery voltage. Active high.
This pin is used to program the device between PWM and LL mode:
HIGH - PWM Mode Only
LOW - LL Mode: PWM operation for loads above 100mA and variable switching
frequency for loads below 100mA. Connecting the SYNC pin to the system clock
(19.8MHz) will override the internal clock and force the switching frequency to
the external clock frequency divided by 10.
Input supply voltage for the converter. Must be closely decoupled.
Main power ground. Connect to the output and input capacitor return.
Switching node. Connect the inductor to this pin. It is connected internally to
the drain of both low- and high-side MOSFETs.
Exposed paddle (bottom). Connect to ground directly beneath the package.
Pin Configuration
TDFN33-12
(Top View)
WLCSP-5
(Top View)
N/C ¹
VOUT ²
VOUT ³
VCC ⁴
AGND ⁵
DAC ⁶
12 _LX
11 _PGND
10 _VIN
9 _MODE/SYNC
8 _BYPASS
7 _EN
11: PGND
8: PGND
LX
VOUT
MODE/SYNC
BYPASS
10 11 12
9
8
7
4
5
6
3
2
1
VIN
VCC
AGND
DAC
5: VOUT
2: EN
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2
201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013