LT8620
65V, 2A Synchronous
Step-Down Regulator
with 2.5A Quiescent
Current
FEATURES DESCRIPTION
n
Wide Input Voltage Range: 3.4V to 65V
The LT 8620 is a compact, high efficiency, high speed
n
Ultralow Quiescent Current Burst Mode Operation:
synchronous monolithic step-down switching regulator
n
2.5A I Regulating 12V to 3.3V
that accepts a wide input voltage range up to 65V, and
Q IN OUT
n
Output Ripple < 10mV
consumes only 2.5A of quiescent current. Top and bottom
P-P
n
High Efficiency Synchronous Operation: power switches are included with all necessary circuitry
n
94% Efficiency at 1A, 12V to 5V to minimize the need for external components. Low ripple
IN OUT
n
92% Efficiency at 1A, 12V to 3.3V Burst Mode operation enables high efficiency down to
IN OUT
n
Fast 30ns Minimum Switch-On Time very low output currents while keeping the output ripple
n
Low Dropout Under All Conditions: 250mV at 1A below 10mV . A SYNC pin allows synchronization to an
P-P
n
external clock. Internal compensation with peak current
Safely Tolerates Inductor Saturation in Overload
n
mode topology allows the use of small inductors and
Low EMI
n results in fast transient response and good loop stability.
Adjustable and Synchronizable: 200kHz to 2.2MHz
n The EN/UV pin has an accurate 1V threshold and can be
Accurate 1V Enable Pin Threshold
n used to program V undervoltage lockout or to shut down
Internal Compensation
IN
the LT8620 reducing the input supply current to 1A. A
n
Output Soft-Start and Tracking
capacitor on the TR/SS pin programs the output voltage
n
Small Thermally Enhanced 16-Lead MSOP and
ramp rate during start-up. The PG flag signals when V
OUT
24-Lead 3mm 5mm QFN Packages
is within 9% of the programmed output voltage as well as
fault conditions. The LT8620 is available in small 16-Lead
APPLICATIONS
MSOP and 3mm 5mm QFN packages with exposed pads
n
Automotive and Industrial Supplies
for low thermal resistance.
n
General Purpose Step-Down
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
n
GSM Power Supplies
owners.
TYPICAL APPLICATION
Efficiency at 5V
OUT
5V 2A Step-Down Converter
100
95
V
IN
V BST
IN
5.5V TO 65V
0.1F 90
4.7F
EN/UV
4.7H
V
OUT
85
5V
PG SW
LT8620 2A
80
47F
SYNC
BIAS
10nF
75
1M
TR/SS FB 70
1F
10pF
65
INTV
CC
60 f = 700kHz
SW
RT GND
V = 12V
IN
55
V = 24V
IN
60.4k 243k
50
0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0
f = 700kHz
SW LOAD CURRENT (A)
8620 TA01a
8620 TA01b
8620fa
1
For more information www.linear.com/LT8620
EFFICIENCY (%)LT8620
ABSOLUTE MAXIMUM RATINGS (Note 1)
V , EN/UV ................................................................65V SYNC Voltage . ............................................................6V
IN
PG .............................................................................42V Operating Junction Temperature Range (Note 2)
BIAS ..........................................................................25V LT8620E ............................................ 40C to 125C
BST Pin Above SW Pin................................................4V LT8620I ............................................. 40C to 125C
FB, TR/SS, RT, INTV . ..............................................4V LT8620H ............................................ 40C to 150C
CC
LT8620MP ......................................... 55C to 150C
Storage Temperature Range .................. 65C to 150C
PIN CONFIGURATION
TOP VIEW
24 23 22 21
SYNC 1 20 FB
TOP VIEW
TR/SS 2 PG
19
SYNC 1 16 FB
RT 3 18 BIAS
TR/SS 2 15 PG
RT 3 14 BIAS
EN/UV 4 17 INTV
CC
25
EN/UV 4 17 13 INTV
CC
GND
V 5 12 BST
GND V 5 16 BST
IN
IN
V 6 11 SW
IN
V 6 15 SW
NC 7 10 SW IN
GND 8 9 SW
NC 7 SW
14
MSE PACKAGE
GND 8 13 SW
16-LEAD PLASTIC MSOP
9 10 11 12
= 40C/W, = 10C/W
JA JC(PAD)
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
UDD PACKAGE
24-LEAD (3mm 5mm) PLASTIC QFN
= 46C/W, = 5C/W
JA JC(PAD)
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT8620EMSE#PBF LT8620EMSE#TRPBF 8620 16-Lead Plastic MSOP 40C to 125C
LT8620IMSE#PBF LT8620IMSE#TRPBF 8620 16-Lead Plastic MSOP 40C to 125C
LT8620HMSE#PBF LT8620HMSE#TRPBF 8620 16-Lead Plastic MSOP 40C to 150C
LT8620MPMSE#PBF LT8620MPMSE#TRPBF 8620 16-Lead Plastic MSOP 55C to 150C
LT8620EUDD#PBF LT8620EUDD#TRPBF LGGV 24-Lead (3mm 5mm) Plastic QFN 40C to 125C
LT8620IUDD#PBF LT8620IUDD#TRPBF LGGV 24-Lead (3mm 5mm) Plastic QFN 40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: