Linear Technology Analog Devices LT8607, Datasheet

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LT8607/LT8607B
1
Rev. C
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TYPICAL APPLICATION
FEATURES DESCRIPTION
42V, 750mA Synchronous
Step-Down Regulator with
2.5µA Quiescent Current
The LT
®
8607 is a compact, high efficiency, high speed syn-
chronous monolithic step-down switching regulator that
consumes only 1.7µA of non-switching quiescent current.
The LT8607 can deliver 750mA of continuous current.
Low ripple Burst Mode operation enables high efficiency
down to very low output currents while keeping the output
ripple below 10mV
P-P
. Internal compensation with peak
current mode topology allows the use of small inductors
and results in fast transient response and good loop sta-
bility. The EN/UV pin has an accurate 1V threshold and
can be used to program V
IN
undervoltage lockout or to
shut down the LT8607 reducing the input supply current
to 1µA. The PG pin signals when V
OUT
is within ±8.5% of
the programmed output voltage as well as fault conditions.
The MSOP package includes a SYNC pin to synchronize
to an external clock, or to select Burst Mode operation
or pulse-skipping with or without spread spectrum; the
TR/SS pin programs soft-start or tracking. The DFN pack-
age omits these pins and can be purchased in pulse-skip-
ping or Burst Mode operation.
APPLICATIONS
Wide Input Voltage Range: 3.0V to 42V
Ultralow Quiescent Current Burst Mode
®
Operation:
n
<3µA I
Q
Regulating 12V
IN
to 3.3V
OUT
n
Output Ripple <10mV
P-P
High Efficiency 2MHz Synchronous Operation:
n
>93% Efficiency at 0.5A, 12V
IN
to 5V
OUT
750mA Maximum Continuous Output
Fast Minimum Switch-On Time: 35ns
Adjustable and Synchronizable: 200kHz to 2.2MHz
Spread Spectrum Frequency Modulation for Low EMI
Allows Use of Small Inductors
Low Dropout
Peak Current Mode Operation
Accurate 1V Enable Pin Threshold
Internal Compensation
Output Soft-Start and Tracking
Small Thermally Enhanced 10-Lead MSOP Package or
8-Lead 2mm × 2mm DFN Package
General Purpose Step-Down Converter
Low EMI Step Down
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5V, 2MHz Step-Down
12V
IN
to 5V
OUT
Efficiency
0.1µF
4.7µF
1µF
22µF
X7R
1206
10pF
4.7µH
18.2k
1M
187k
100k
10nF
V
IN
EN/UV
SYNC
LT8607
INTV
CC
TR/SS
RT
GND
FB
PG
SW
BST
V
IN
5.7V to 42V
V
OUT
5V
750mA
POWER
GOOD
f
SW
= 2MHz
8607 TA01a
f
SW
= 2MHz
L = 4.7µH
I
OUT
(mA)
0 125 250 375 500 625 750
50
55
60
65
70
75
80
85
90
95
100
EFFICIENCY (%)
8607 TA01b
PACKAGE SYNC FUNCTIONALITY
LT8607MSE MSE Programmable
LT8607DFN DFN Burst Mode Operation
LT8607BDFN DFN Pulse-Skipping Mode