Linear Technology LTC3444 User manual

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 901
MICROPOWER SYNCHRONOUS BUCK-BOOST CONVERTER FOR CDMA AND HSDPA
1
LTC3444
DESCRIPTION
Demonstration circuit 901A features the LTC3444 and is
a highly efficient, 1.5MHz fixed frequency buck-boost
DC/DC converter. The input voltage can range from 3.1V
to 5.0V and is suitable for Li-Ion or three-cell NiCd/NiMH
battery applications while the output voltage can be set
anywhere from 0.8V to 4.2V by injecting a 0.35V – 2.4V
Control Signal.
The DC901A has been optimized for use in 3G WCDMA
applications. High efficiency is achieved at very low out-
put voltages while component count is minimized. The
board provides the fast transient response required to
slew the RF power amplifier from standby to transmit
and transmit to standby levels. Output overvoltage pro-
tection protects the RF power amplifier.
Design files for this circuit board are available. Call
the LTC factory.
QUICK START PROCEDURE
Refer to Figure 1 for proper measurement equipment
setup and follow the procedure below:
1. Start with Load set to 0A.
2. Set Power Supply 1 to 3.3V and Power Supply 2 to
1V.
3. The Load can be set from 0 – 400mA.
Figure 1. Proper Measurement Equipment Setup

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 901
MICROPOWER SYNCHRONOUS BUCK-BOOST CONVERTER FOR CDMA AND HSDPA
2
Demo Board Parameters:
Parameter Condition Value
Input Voltage Range 3.1V – 5.0V
Maximum Load Current Vout = 0.8V – 4.2V 400mA
VCONTROL Range 0.35V – 2.4V*
Operating Frequency 1.5MHz
* See Table 1 in LTC3444 Datasheet.

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 901
MICROPOWER SYNCHRONOUS BUCK-BOOST CONVERTER FOR CDMA AND HSDPA
3

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 901
MICROPOWER SYNCHRONOUS BUCK-BOOST CONVERTER FOR CDMA AND HSDPA
4

Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Analog Devices Inc.:
DC901A