Datasheet ADP1853 (Analog Devices)

Synchronous, Step-Down DC-to-DC Controller with Voltage Tracking and Synchronization Data Sheet ADP1853 FEATURES
current, improve EMI, and reduce the size of the input bulk
Input voltage range: 2.75 V to 20 V
capacitance. The ADP1853 can also be configured as a slave
Output voltage range: 0.6 V to 90% V
device for current sharing. Additionally, the ADP1853 includes
IN Maximum output current of more than 25 A
accurate tracking, precision enable, and power good functions
Current mode architecture with current sense input
for sequencing. The ADP1853 provides a high speed, high peak
Configurable to voltage mode
current gate driving capability to enable energy efficient power
±1% output voltage accuracy over temperature
conversion. The device can be configured to operate in power
Voltage tracking input
saving mode by skipping pulses, reducing switching losses and
Programmable frequency: 200 kHz to 1.5 MHz
improving efficiency at light load and standby conditions.
Synchronization input
The accurate current limit allows design within a narrower
Internal clock output
range of tolerances and can reduce overal converter size and
Power saving mode at light load
cost. The ADP1853 can regulate down to 0.6 V output using a
Precision enable input
high accuracy reference with ±1% tolerance over the
Power good with internal pull-up resistor
temperature range from −40°C to 125°C.
Adjustable soft start
With a wide range input voltage, the ADP1853 is designed to
Programmable current sense gain
provide the designer with maximum flexibility for use in a
Integrated bootstrap diode
variety of system configurations; loop compensation, soft start,
Starts into a precharged load
frequency setting, power saving mode, current limit, and
Externally adjustable slope compensation
current sense gain can all be programmed using external
Suitable for any output capacitor
components. In addition, the external RAMP resistor allows
Overvoltage and overcurrent-limit protection
choosing optimal slope and V
Thermal overload protection
IN feedforward in both current and voltage mode for excellent line rejection. The linear
Input undervoltage lockout (UVLO)
regulator and the boot strap diode for the high-side driver are
Available in 20-lead, 4 mm × 4 mm LFCSP Supported by ADIsimPower™ design tool
internal. Protection features include undervoltage lock out, overvoltage,
APPLICATIONS
overcurrent/short circuit, and overtemperature.
Intermediate bus and POL systems requiring sequencing and tracking, including VIN RRAMP Telecom base station and networking VMA Industrial and Instrumentation RAMP VIN Medical and healthcare M1 EN L DH BST VOUT GENERAL DESCRIPTION TRK SW
The ADP1853 is a wide range input, dc-to-dc, synchronous
VCCO CS ILIM
buck controller capable of running from commonly used 3.3 V
ADP1853 M2
to 12 V (up to 20 V) voltage inputs. The device nominal y
DL R
operates in current mode with valley current sensing providing
CSG SYNC PGND
the fastest step response for digital loads. It can also be
HI FB FREQ LO
configured as a voltage mode control er with low noise and
SS COMP
crosstalk for sensitive loads.
PGOOD AGND
001 The ADP1853 can be used as a master synchronization clock
CLKOUT
10594- for the power system and for convenient synchronization Figure 1. Typical Operation Circuit between control ers. The CLKOUT signal can synchronize other devices in the ADP185x family such that slave devices are phase-shifted from the master to reduce the input ripple
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Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION SIMPLIFIED BLOCK DIAGRAM PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CONTROL ARCHITECTURE OSCILLATOR FREQUENCY SYNCHRONIZATION PWM OR PULSE SKIP MODE OF OPERATION CLKOUT SIGNAL SYNCHRONOUS RECTIFIER AND DEAD TIME INPUT UNDERVOLTAGE LOCKOUT INTERNAL LINEAR REGULATOR OVERVOLAGE PROTECTION POWER GOOD SHORT-CIRCUIT AND CURRENT-LIMIT PROTECTION ENABLE/DISABLE CONTROL THERMAL OVERLOAD PROTECTION INTERLEAVED DUAL-PHASE OPERATION APPLICATIONS INFORMATION ADISIMPOWER DESIGN TOOL SETTING THE OUTPUT VOLTAGE SOFT START SETTING THE CURRENT LIMIT ACCURATE CURRENT-LIMIT SENSING INPUT CAPACITOR SELECTION VIN PIN FILTER BOOST CAPACITOR SELECTION INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION MOSFET SELECTION LOOP COMPENSATION—VOLTAGE MODE Type III Compensation LOOP COMPENSATION—CURRENT MODE Setting the Slope Compensation Setting the Current Sense Gain Type II Compensation SWITCHING NOISE AND OVERSHOOT REDUCTION VOLTAGE TRACKING Coincident Tracking Ratiometric Tracking PCB LAYOUT GUIDLINES TYPICAL OPERATING CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE