LT8610AC_15 Datasheet, PDF (1/26 Pages) Linear Technology – 42V, 3.5A Synchronous Step-Down Regulator with 2.5A Quiescent Current

Features
n _{LT8610 Feature Set, Plus:}
3V Minimum Input Voltage
800mV Feedback Voltage
3.5A Maximum Output Current
Fast 30ns Minimum Switch-On Time
Improved Burst Mode Efficiency
Improved EMI
n _{Wide Input Voltage Range: 3V to 42V}
n _{Ultralow Quiescent Current Burst Mode}^® _Operation:
2.5μA I_Q Regulating 12V_IN to 3.3V_OUT
n _{High Efficiency Synchronous Operation:}
95% Efficiency at 1A, 5V_OUT from 12V_IN
93% Efficiency at 1A, 3.3V_OUT from 12V_IN
n _{Low Dropout Under All Conditions: 200mV at 1A}
n _{Safely Tolerates Inductor Saturation in Overload}
n _{Adjustable and Synchronizable Frequency:}
LT8610AC: 200kHz to 2.2MHz
LT8610AC-1: 1.5MHz to 2.2MHz
n _{Accurate 1.015V Enable Pin Threshold}
n _{Output Soft-Start and Tracking}
n _{Small Thermally Enhanced 16-Lead MSOP Package}
Applications
n _{Automotive and Industrial Supplies}
n _{GSM Power Supplies}
LT8610AC/LT8610AC-1
42V, 3.5A Synchronous
Step-Down Regulator with
2.5µA Quiescent Current
Description
The LT^®8610AC/LT8610AC-1 is a compact, high efficiency,
high speed synchronous monolithic step-down switching
regulator that consumes only 2.5µA of quiescent current.
Compared to the LT8610AB, the LT8610AC/LT8610AC-1
has a lower feedback voltage of 800mV and a lower mini-
mum V_IN of 3V. The LT8610AC/LT8610AC-1 has the same
additional features of the LT8610AB as compared to the
LT8610: higher maximum output current of 3.5A, faster
minimum on time of 30ns, and higher light load efficiency.
The LT8610AC/LT8610AC-1 has a SYNC pin for syn-
chronization to an external clock. A capacitor on the TR/
SS pin programs the output voltage ramp rate during
startup. The PG flag signals when V_OUT is within ±8% of
the programmed output voltage as well as fault conditions.
The LT8610AC-1 has internal compensation optimized for
high switching frequencies resulting in improved transient
response compared to the LT8610AC. The LT8610AC-1
also has a feature which will soft-start the part when
exiting dropout or brownout conditions reducing output
voltage overshoot.
LT8610AC
FEEDBACK
OUTPUT MIN ON IMPROVED
VOLTAGE MIN V_IN CURRENT TIME
EMI
0.80V
3.0V
3.5A 30ns
Yes
LT8610AB* 0.97V
3.4V
3.5A 30ns
Yes
LT8610A* 0.97V
3.4V
3.5A 30ns
Yes
LT8610*
0.97V
3.4V
2.5A 50ns
–
*See LT8610A/LT8610AB or LT8610 data sheet.
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 owners.
Typical Application
5V 3.5A Step-Down Converter
V_IN
5.5V TO 42V
4.7µF
10nF
1µF
V_IN
BST
EN/UV
PG ^LT8610AC SW
SYNC
BIAS
TR/SS
FB
INTV_CC
RT GND
60.4k
0.1µF
4.7µH
1M
10pF
191k
f_SW = 700kHz
8610ac1 TA01a
V_OUT
5V
47µF _3.5A
×2
Efficiency at 5V_OUT
100
90
80
70
60
50
40
30
0.1
V_IN = 12V
V_IN = 24V
V_IN = 36V
1
10
100
LOAD CURRENT (mA)
1000
8610ac1 TA01b
For more information www.linear.com/LT8610AC
8610acfa
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