LTC3626_15 Datasheet, PDF (1/28 Pages) Linear Technology – 20V, 2.5A Synchronous Monolithic Step-Down Regulator with Current and Temperature Monitoring

LTC3626
20V, 2.5A Synchronous
Monolithic Step-Down Regulator with
Current and Temperature Monitoring
Features
nn _{3.6V to 20V Input Voltage Range}
nn _{Wide Output Voltage Range of 0.6V to 97% VIN Opti-}
mized for 0.6V to 6V
nn _{Low RDS(ON) Integrated Switches Provide Up to 95%}
Efficiency
nn _{Up to 2.5A of Output Current}
nn _{Average Input and Output Current Monitoring}
nn _{Programmable Average Input/Output Current Limit}
nn _{Die Temperature Monitor and Programmable Limit}
nn _{Adjustable Switching Frequency: 500kHz to 3MHz}
nn _{External Frequency Synchronization}
nn _{Current Mode Operation for Excellent Line and Load}
Transient Response
nn _{0.6V Reference with 1% Accuracy Over Temperature}
nn _{User Selectable Burst Mode}^® _{Operation or Forced}
Continuous Operation
nn _{Short-Circuit Protected}
nn _{Output Voltage Tracking Capability}
nn _{Power Good Status Output}
nn _{Available in Small, Thermally Enhanced, 20-Lead}
(3mm × 4mm) QFN Package
Applications
nn _{Distributed Power Systems}
nn _{Battery-Powered Instruments}
nn _{Point-of-Load Power Supply}
Description
The LTC^®3626 is a high efficiency, monolithic synchronous
buck regulator using a phase-lockable controlled on-time,
current mode architecture capable of supplying up to 2.5A
of output current. The operating supply voltage range is
3.6V to 20V, making it suitable for a wide range of power
supply applications.
The operating frequency is programmable from 500kHz to
3MHz with an external resistor allowing the use of small
surface mount inductors. For applications sensitive to
switching noise, the LTC3626 can be externally synchro-
nized over the same frequency range. An internal phase-
locked loop aligns the on-time of the top power MOSFET to
the internal or external clock. This unique controlled on-time
architecture is ideal for high step-down ratio applications
that demand high switching frequencies and fast transient
response. An internal phase lock loop servos the on-time
of the internal one-shot timer to match the frequency of
the internal clock or an applied external clock.
The LTC3626 offers two operational modes: Burst
Mode and forced continuous mode to allow the user
to optimize output voltage ripple, noise and light load
efficiency for a given application.
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered and Hot
Swap is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents, including 5481178, 5847554, 6580258,
6304066, 6476589, 6774611, 5994885.
Typical Application
V_IN
3.6V TO 20V
PV_IN
47µF
SV_IN
RUN
BOOST
LTC3626
PGOOD
INTV_CC
2.2µF
TRACK/SS
SW
ITH
MODE/SYNC V_ON
TSET
IMON_IN
FB
TMON
RT
IMON_OUT
1µF 5.1k ^{SGND PGND}
0.1µF
2.2µH
324k
115k
22pF
V_OUT
3.3V
47µF ^2.5A
25.5k
3626 TA01
For more information www.linear.com/LTC3626
Efficiency vs Load Current
100
V_OUT = 3.3V
90
80
10
70
60
1
50
40
0.1
30
20
Burst Mode
OPERATION
0.01
10
V_IN = 12V
V_IN = 5V
0
0.001
1
10
100
1000 10000
LOAD CURRENT (mA)
3626 TA01b
3626fa
1