LTC3532 LINER [Linear Technology], LTC3532 Datasheet - Page 5

• Manufacturer Part Number: LTC3532
• Description: Micropower Synchronous Buck-Boost DC/DC Converter
• Manufacturer: LINER [Linear Technology]

TYPICAL PERFOR A CE CHARACTERISTICS
PI FU CTIO S
RT (Pin 1): Timing Resistor to Program the Oscillator
Frequency. The programming range is 300kHz to 2MHz.
BURST (Pin 2): Used to Set the Automatic Burst Mode Op-
eration Threshold. Place a resistor and capacitor in parallel
from this pin to ground. See the Applications Information
section for component value selection. For manual control,
ground the pin to force Burst Mode operation, connect to
V
SW1 (Pin 3): Switch Pin Where the Internal Switches A
and B are Connected. Connect inductor from SW1 to SW2.
OUT
2VDIV
2VDIV
SW1
SW2
U
f(kHz) =
to force fi xed frequency mode.
Switch Pins Before Entering
Buck Mode
V
VOUT = 3.3V
I
LOAD
IN
= 4V
= 100mA
U
100mV/DIV
500mA/DIV
R
INDUCTOR
48,000
CURRENT
T
5V/DIV
5V/DIV
(kΩ)
V
SW1
SW2
OUT
40ns/DIV
Burst Mode, Buck-Boost
U
V
V
I
C
LOAD
IN
OUT
OUT
= 3.75V
= 3.3V
= 22μF
= 20mA
W
3535 G13
4μs/DIV
U
50mV/DIV
50mV/DIV
50mV/DIV
V
V
V
OUT
OUT
OUT
Output Ripple at 100mA Load
V
I
C
340612 G16
OUT
OUT
OUT
= 100mA
= 3.6V
= 10μF
V
V
V
IN
IN
IN
= 2.4V
= 3.6V
= 4.5V
400ns/DIV
An optional Schottky diode can be connected from SW1
to ground. Minimize trace length to minimize EMI.
SW2 (Pin 4): Switch Pin Where the Internal Switches C
and D are Connected. For applications with output voltages
over 4.3V, a Schottky diode is required from SW2 to V
to ensure SW2 does not exhibit excess voltage.
GND (Pin 5): Signal and Power Ground for the IC.
V
capacitor is placed from V
V
inductor through SW1 and supplies internal V
IC. A ceramic bypass capacitor as close to the V
GND (Pin 5) is required.
OUT
IN
(Pin 7): Input Supply Pin. Supplies current to the
100mV/DIV
500mA/DIV
(Pin 6): Output of the Synchronous Rectifi er. A fi lter
INDUCTOR
CURRENT
5V/DIV
5V/DIV
V
SW1
SW2
OUT
T
3535 G14
A
V
V
I
C
= 25°C, unless otherwise specifi ed.
Burst Mode, Buck
LOAD
IN
OUT
OUT
= 4.2V
= 3.3V
= 22μF
= 20mA
100mV/DIV
500mA/DIV
INDUCTOR
CURRENT
5V/DIV
5V/DIV
V
SW1
SW2
OUT
Burst Mode, Boost
V
V
I
C
LOAD
4μs/DIV
IN
OUT
OUT
OUT
= 2.4V
= 3.3V
= 22μF
= 20mA
to GND.
4μs/DIV
LTC3532
3535 G17
CC
IN
pin and
for the
3535 G15
3532fc
5
OUT