ADP2311:Dual 1 A, 18 V, Synchronous Step-Down Regulator with Fail-Safe Voltage Monitoring0 pages

Dual 1 A, 18 V, Synchronous Step-Down
Regulator with Fail-Safe Voltage Monitoring

ADP2311

Data Sheet

TYPICAL APPLICATION CIRCUIT

Input voltage: 4.5 V to 18 V
±1.0% output accuracy
Integrated MOSFET: 110 mΩ/60 mΩ typical
Continuous output current: 1 A/1 A
Power fail comparator generates warning
Power-on reset with programmable delay timer
Adjustable voltage monitor for power-down (Channel 2)
Watchdog refresh input
Dual phase with 180° out-of-phase operation
Fixed switching frequency: 300 kHz
Internal compensation and soft start
Stable with low ESR output ceramic capacitors
Precision enable input
Power feedback during power-off
UVLO, OCP, OVP, and thermal shutdown protection

PFO POR WDI
EN
PVIN1

VIN

RSTO
RVM2_TOP

PFI

CIN2

VM2

RPFI_BOT

RVM2_BOT
BST1

C1BST
VOUT1

VIN

PVIN2

RPFI_TOP

CIN1

ADP2311

BST2
SW2
PGND2

SW1
PGND1

RTOP1

COUT1

C2BST
L2

L1

FB1
RBOT1

RTOP2

VOUT2
COUT2

FB2

GND VREG

TIMER

CVREG

RBOT2
11036-001

FEATURES

CTIMER

Figure 1.
100
VOUT = 3.3V
VOUT = 5V

95
90

APPLICATIONS
EFFICIENCY (%)

85

Industrial and instrumentation
Healthcare and medical
DC-to-DC point of load applications

80
75
70
65
60

50

0

0.2

0.4

0.6

0.8

1.0

OUTPUT CURRENT (A)

11036-002

55

Figure 2. Efficiency vs. Output Current at VIN = 12 V, fSW = 300 kHz

GENERAL DESCRIPTION
The ADP2311 is a fully integrated, dual output, synchronous
step-down dc-to-dc regulator. The regulator operates from input
voltages of 4.5 V to 18 V, and the output can regulate down to
0.6 V. Each channel can provide up to 1 A of continuous output
current.

An on-chip watchdog timer can reset the microprocessor if it
fails to strobe within a preset timeout period. Accurate voltage
monitoring circuitry and a power fail comparator provide a
controlled power-up and power-down sequence to enhance
system reliability.

The ADP2311 integrates the high-side and low-side MOSFETs
to provide a very high efficiency, compact solution. Both channels
of the regulator run at 180° out of phase to reduce the input ripple
current and the input capacitor size, thereby helping to lower
system electromagnetic interference (EMI). The ADP2311 also
integrates internal compensation and soft start circuitry to simplify
the design.

The ADP2311 also includes undervoltage lockout (UVLO),
overvoltage protection (OVP), overcurrent protection (OCP),
and thermal shutdown (TSD).

Rev. A

The ADP2311 operates over the −40°C to +125°C junction
temperature range and is available in a 24-lead LFCSP package.

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