LT1076-5_1 Datasheet, PDF (1/8 Pages) Linear Technology – 5V Step-Down Switching Regulator

LT1076-5
5V Step-Down
Switching Regulator
FEATURES
n _{Fixed 5V Output}
n _{2A On-Board Switch}
n _{100kHz Switching Frequency}
n _{2% Output Voltage Tolerance Over Temperature}
n _{Greatly Improved Dynamic Behavior}
n _{Available in Low Cost 5- and 7-Lead Packages}
n _{Only 9.5mA Quiescent Current}
n _{Operates Up to 60V Input}
APPLICATIONS
n _{5V Output Buck Converter}
n _{Tapped Inductor Buck Converter with 4A Output at}
5V
n _{Positive-to-Negative Converter}
DESCRIPTION
The LT^®1076-5 is a 2A fixed 5V output monolithic bipolar
switching regulator which requires only a few external parts
for normal operation. The power switch, all oscillator and
control circuitry, all current limit components, and an output
monitor are included on the chip. The topology is a classic
positive “buck” configuration but several design innova-
tions allow this device to be used as a positive-to-negative
converter, a negative boost converter, and as a flyback con-
verter. The switch output is specified to swing 40V below
ground, allowing the LT1076-5 to drive a tapped inductor
in the buck mode with output currents up to 4A.
The LT1076-5 uses a true analog multiplier in the feedback
loop. This makes the device respond nearly instantaneously
to input voltage fluctuations and makes loop gain indepen-
dent of input voltage. As a result, dynamic behavior of the
regulator is significantly improved over previous designs.
On-chip pulse by pulse current limiting makes the LT1076-
5 nearly bust-proof for output overloads or shorts. The
input voltage range as a buck converter is 8V to 60V, but
a self-boot feature allows input voltages as low as 5V in
the inverting and boost configurations.
The LT1076-5 is available in a low cost 5- and 7-lead TO-
220 packages with frequency pre-set at 100kHz and current
limit at 2.6A. See Application Note 44 for design details.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Basic Positive Buck Converter
8V TO 40V
+
V_IN
V_SW
LT1076-5
SENSE
GND
V_C
C3
200μF
R3
1.5k
C2
0.033μF
100μH**^†
MBR340*
5V
≤1.8A
* MBR330P MAY BE USED
FOR V_IN ≤ 25V
** COILTRONICS #100-1-52
HURRICANE #HL-AG210LL
+ _C1
500μF
25V
† _{VALUE MAY BE REDUCED TO 50μH}
FOR OUTPUT LOADS BELOW 1.5A
LT1076-5 TA01
10765fc
1