Datasheet
FB
VIN
VCC
REGULATOR
DRIVER
HB
ADAPTIVE
TIMER
EN
UVLO
UVLO
ERROR
AMP
DIS
COMP
CLK
S
R
Q
Q
OSCILLATOR
AGND
CLK
CSG
RAMP GENERATOR
+
SLEEP
MODE
SHUTDOWN
PWM
CURRENT
LIMIT
RAMP
SS
VIN
10 x R
S
V/A
5 PA
1V
10 PA
CS
DRIVER
PGND
LO
VOUT
HO
SW
1
2
3
4
5 146
15
10
13
12
20
19
18
+
-
4.5V
17
HICCUP FAULT TIMER
256 CLOCK CYCLES
UVLO
LOGIC
STANDBY
UVLO
7
8
9
16
VCCX
R
T
A =10
VCC
DEMB
11
TRACK
SAMPLE
and
HOLD
CLK
DIODE
EMULATION
CONTROL
SS
SW
THERMAL
SHUTDOWN
3V
VCCX
EN
SYNC
1.215V
C
COMP
R
COMP
C
HF
1
0.5V
R
S
C
SNUB
V
OUT
R
SNUB
C
OUT
Q2
Q1
L1
R
FB1
R
FB2
I
R
D1
C
VCC
C
VCCX
V
IN
C
HB
RT/SYNC
C
RAMP
C
SYNC
1.215V
7. 4 V
LM5116
R
EN
R
UV2
R
UV1
C
IN
C
FT
C
SS
V
IN
6V -100V
D2
I
R
= 5PA (VIN - VOUT) + 25PA
V x /
.6V
LM5116
SNVS499G –FEBRUARY 2007–REVISED MARCH 2013
www.ti.com
BLOCK DIAGRAM AND TYPICAL APPLICATION CIRCUIT
Figure 26. Typical Application
Detailed Operating Description
The LM5116 high voltage switching regulator features all of the functions necessary to implement an efficient
high voltage buck regulator using a minimum of external components. This easy to use regulator integrates high-
side and low-side MOSFET drivers capable of supplying peak currents of 2 Amps. The regulator control method
is based on current mode control utilizing an emulated current ramp. Emulated peak current mode control
provides inherent line feed-forward, cycle by cycle current limiting and ease of loop compensation. The use of an
emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable processing
of the very small duty cycles necessary in high input voltage applications. The operating frequency is user
programmable from 50 kHz to 1 MHz. An oscillator/synchronization pin allows the operating frequency to be set
by a single resistor or synchronized to an external clock. Fault protection features include current limiting, thermal
shutdown and remote shutdown capability. An under-voltage lockout input allows regulator shutdown when the
input voltage is below a user selected threshold, and an enable function will put the regulator into an extremely
low current shutdown via the enable input. The HTSSOP-20 package features an exposed pad to aid in thermal
dissipation.
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