Dual 1 A, 18 V, Synchronous Step-Down

Regulator with Fail-Safe Voltage Monitoring

Data Sheet

ADP2311

Rev. B

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FEATURES

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

APPLICATIONS

Industrial and instrumentation

Healthcare and medical

DC-to-DC point of load applications

TYPICAL APPLICATION CIRCUIT

BST1

PVIN1

SW1

EN

FB1

GND VREG

ADP2311

PGND1

BST2

PVIN2

SW2

VM2

FB2

PGND2

L2

TIMER

PFO POR

PFI

WDI

RSTO

L1

Figure 1.

50

55

60

65

70

75

80

85

90

95

100

0

0.2

0.4

0.6

0.8

1.0

OUTPUT CURRENT (A)

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.

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.

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 also includes undervoltage lockout (UVLO),

overvoltage protection (OVP), overcurrent protection (OCP),

and thermal shutdown (TSD).

The ADP2311 operates over the −40°C to +125°C junction

temperature range and is available in a 24-lead LFCSP package.