LT3437,LT3437EDD,LT3437EFE,LT3437IDD,LT3437IFE

Part No.:
LT3437,LT3437EDD,LT3437EFE,LT3437IDD,LT3437IFE
Download:
Download
Description:
High Voltage 500mA, 200kHz Step-Down Switching Regulator with 100?A Quiescent Current
File Size:
524 K
Page:
24 Pages
Logo:
Maker:
LINER [ LINEAR TECHNOLOGY ]
PCB Prototype

July 16, 2018:

LT3694

LTC1864

LTC2208CUP-14

LTC3250

LTC3446EDE

LTC4055

LTC4440_09

LTC6240CS5-TRPBF

LTM4605

LTM4627

LXMG1813-12-62S

M1540P-R10851-HD

PCB Datasheet:1PCB Datasheet:1
LT3437
High Voltage 500mA, 200kHz
Step-Down Switching Regulator
with 100µA Quiescent Current
FEATURES
DESCRIPTIO
Wide Input Range: 3.3V to 60V
Load Dump (Input Transient) Protection to 80V
500mA Peak Switch Current
Burst Mode
®
Operation: 100µA Quiescent Current**
Low Shutdown Current: I
Q
< 1µA
Burst Mode Operation Defeat
200kHz Switching Frequency
Saturating Switch Design: 0.8Ω On-Resistance
Peak Switch Current Maintained Over
Full Duty Cycle Range*
1.25V Feedback Reference Voltage
Easily Synchronizable
Soft-Start Capability
Small 10-Pin Thermally Enhanced DFN Package
The LT
®
3437 is a 200kHz monolithic buck switching
regulator that accepts input voltages up to 80V. A high
efficiency 500mA, 0.8Ω switch is included on the die along
with all the necessary oscillator, control and logic cir-
cuitry. Current mode topology is used for fast transient
response and good loop stability.
Innovative design techniques along with a new high volt-
age process achieve high efficiency over a wide input
range. Efficiency is maintained over a wide output current
range by employing Burst Mode operation at low currents,
utilizing the output to bias the internal circuitry, and by
using a supply boost capacitor to fully saturate the power
switch. Burst Mode operation can be defeated by a logic
high signal on the SYNC pin which results in lower light
load ripple at the expense of light load efficiency. Patented
circuitry maintains peak switch current over the full duty
cycle range.* Shutdown reduces input supply current to
less than 1µA. External synchronization can be imple-
mented by driving the SYNC pin with logic-level inputs. A
single capacitor from the C
SS
pin to the output provides a
controlled output voltage ramp (soft-start).
The LT3437 is available in a low profile (0.75mm) 3mm
×
3mm 10-pin DFN package or a 16-Pin TSSOP Package
both with exposed pad leadframes for low thermal
resistance.
APPLICATIO S
High Voltage Power Conversion
14V and 42V Automotive Systems
Industrial Power Systems
Distributed Power Systems
Battery-Powered Systems
Powered Ethernet
, LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode
is a registered trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. *Protected by U.S. Patents including 6498466. **See
Burst Mode Operation section for conditions.
TYPICAL APPLICATIO
V
IN
4.5V TO 80V*
V
IN
SHDN
LT3437
V
C
1500pF
25k
SYNC
GND
FB
330pF
C
SS
V
BIAS
27pF
BOOST
0.1µF
SW
0.1µF
14V to 3.3V Step-Down Converter with
100µA No Load Quiescent Current
SUPPLY CURRENT (µA)
2.2µF
100V
CER
100µH BAS21
10MQ100N
V
OUT
3.3V
400mA
Supply Current vs Input Voltage
200
180
160
140
120
100
80
60
40
20
3437 TA01
165k
100k
100µF
6.3V
TANT
*FOR INPUT VOLTAGES ABOVE 60V RESTRICTIONS APPLY
0
0
10
20
30 40 50 60
INPUT VOLTAGE (V)
70
80
3435 TA02
U
Input Voltage
Transient Response
V
IN
20V/DIV
V
IN
0V
V
OUT
20mV/DIV
AC COUPLED
I
OUT
250mA
LOAD DUMP
50ms/DIV
COLD CRANK
3437 TA03
U
U
3437f
1