LT1339_15 Datasheet, PDF (1/20 Pages) Linear Technology – High Power Synchronous DC/DC Controller

FEATURES
s _{High Voltage: Operation Up to 60V}
s _{High Current: Dual N-Channel Synchronous Drive}
Handles Up to 10,000pF Gate Capacitance
s _{Programmable Average Load Current Limiting}
s _{5V Reference Output with 10mA External}
Loading Capability
s _{Programmable Fixed Frequency Synchronizable}
Current Mode Operation Up to 150kHz
s _{Undervoltage Lockout with Hysteresis}
s _{Programmable Start Inhibit for Power Supply}
Sequencing and Protection
s _{Adaptive Nonoverlapping Gate Drive Prevents}
Shoot-Through
U
APPLICATIONS
s _{48V Telecom Power Supplies}
s _{Personal Computers and Peripherals}
s _{Distributed Power Converters}
s _{Industrial Control Systems}
s _{Lead-Acid Battery Backup Systems}
s _{Automotive and Heavy Equipment}
LT1339
High Power Synchronous
DC/DC Controller
DESCRIPTION
The LT^®1339 is a high power synchronous current mode
switching regulator controller. The IC drives dual
N-channel MOSFETs to create a single IC solution for high
power DC/DC converters in applications up to 60V.
The LT1339 incorporates programmable average current
limiting, allowing accurate limiting of DC load current
independent of inductor ripple current. The IC also incor-
porates user-adjustable slope compensation for minimi-
zation of magnetics at duty cycles up to 90%.
The LT1339 timing oscillator operating frequency is pro-
grammable and can be synchronized up to 150kHz. Mini-
mum off-time operation provides main switch protection.
The IC also incorporates a soft start feature that is gated by
both shutdown and undervoltage lockout conditions.
An output phase reversal pin allows flexibility in configu-
ration of converter types, including inverting and negative
topologies.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
C_5VREF
1µF
R_CT
10k
C_CT
C_AVG
2200pF 2200pF
C_VC, 1nF
C_SS, 1µF
R_VC, 10k
C_REF
0.1µF
R_FB2
1k
28V to 5V 20A Buck Converter
SYNC
V_BOOST
5V_REF
TG
CT
TS
SL/ADJ
12V_IN
LT1339 BG
I_AVG
SS
PGND
PHASE
V_C
RUN/SHDN
SGND
SENSE⁺
V_FB
V_REF
SENSE^–
R_FB1
3k
DBST
IN5819
CBST
1µF
D1
MBR0520
R_RUN
100k
D2
MBR0520
L1 = CTX02-13400-X2
12V
C_12VIN
47µF
V_IN
28V
IRL3803
IRL3103D2
×2
C_IN
100
1500µF
63V
×3
90
80
70
L1
10µH
60
50
0
R_S
0.005Ω _VOUT
C_OUT ^{5V AT 20A}
2200µF
6.3V
×2
1339 TA03
28V to 5V Efficiency
5
10
15
20
OUTPUT CURRENT (A)
1339 TA03a
sn1339 1339fas
1