LTC3530 LINER [Linear Technology], LTC3530 Datasheet - Page 5

• Manufacturer Part Number: LTC3530
• Description: Wide Input Voltage Synchronous Buck-Boost DC/DC Converter
• Manufacturer: LINER [Linear Technology]

TYPICAL PERFORMANCE CHARACTERISTICS
100mV/DIV
PIN FUNCTIONS
R
lator. Connect a resister from R
BURST (Pin 2): Used to Set the Automatic Burst Mode
Threshold. Connect 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
0.25A/DIV
IN
T
f(kHz) = 33,170/R
(Pin 1): Programs the Frequency of the Internal Oscil-
LOAD
to force fi xed frequency PWM mode.
V
OUT
Load Transient Response in Fixed
Frequency Mode, No Load to 300mA
V
V
C
IN
OUT
OUT
= 3.6V
= 3.3V
= 22μF , X5R CERAMIC
200mV/DIV
INDUCTOR
CURRENT
0.5A/DIV
BURST
2V/DIV
V
OUT
100μs/DIV
T
Transition from Burst Mode
Operation to Fixed Frequency Mode
C
(kΩ)
OUT
= 22μF , X5R CERAMIC
T
to ground.
200μs/DIV
3530 G13
100mV/DIV
0.25A/DIV
LOAD
V
OUT
Load Transient Response in
Auto Burst Mode Operation,
No Load to 500mA
V
V
C
LOW ESR TANTALUM
IN
OUT
OUT
3530 G16
= 3.6V
= 3.3V
= 47μF , X5R CERAMIC + 100μF
100μs/DIV
SW1 (Pin 3): Switch Pin Where the Internal Switches A and
B are Connected. Connect inductor from SW1 to SW2. An
optional Schottky diode can be connnected from SW1 to
ground for a moderate effi ciency improvement. Minimize
trace length to keep EMI down.
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 the SW pin does not exhibit excessive voltage.
2000
1800
1600
1400
1200
1000
600
800
400
200
T
3530 G14
1.5
Maximum Output Current vs V
A
= 25°C, unless otherwise specifi ed.
INDUCTOR
250mA AT 1.8V
50mV/DIV
CURRENT
0.25A/DIV
2.5
V
OUT
C
Typical Burst Mode Waveforms
I
OUT
V
OUT
IN
3.5
(V)
= 22μF , X5R CERAMIC
4.5
22μs/DIV
LTC3530
IN
3530 G17
5.5
3530 G15
3530fb
5
OUT