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Description

1

Description

The TPS51916EVM-746 is designed to use a regulated 12-V bus to produce a regulated 1.5-VDDQ output

at up to a 20-A load current. The TPS51916EVM-746 demonstrates TPS51916 in a typical DDR3

application with D-CAP2

™-mode operation. The EVM also provides test points to evaluate the

performance of the TPS51916.

1.1

Typical Applications

•

DDR2/DDR2/DDR3L/DDR4 memory power supplies

•

SSTL_18, SSTL_15, SSTL_135, and HSTL termination

1.2

Features

The TPS51916EVM-746 features:

•

D-CAP2

™-mode operation with all-ceramic VDDQ output capacitor

•

20-Adc steady-state VDDQ output current

•

Support VDDQ prebias start-up

•

SW1 and SW2 provides S3, S5 power control

•

Optional external VLDOIN voltage for efficiency and flexible operation

•

Convenient test points for probing critical waveforms

2

Electrical Performance Specifications

Table 1. TPS51916EVM-746 Electrical Performance Specifications

Parameter

Test Conditions

Min

Typ

Max

Units

Input Characteristics

Voltage range

VIN

8

12

20

V

V5IN

4.5

5

5.5

Maximum input current

4.21

A

No-load input current

0.1

mA

VDDQ Output

DDR3 (Default setting), R15 = 47.5k, R16 = 2k

1.5

V

DDR2, R15 = R16= Open

1.8

V

VDDQ Output voltage

(VDDQSNS)

DDR3L, R15 = 28k, R16 = 2k

1.35

V

DDR4, R15 = 18.2k, R16 = 2k

1.2

V

VDDQ Output voltage regulation

Line regulation (Vin = 8 V

–20 V)

0.2%

0.5%

Output voltage ripple

20

mVpp

Output load current

0

20

A

Output overcurrent

30

A

Switching frequency

500

kHz

Peak efficiency

Vin = 12 V, 1.5 VDDQ/8 A

90.93%

Full-load efficiency

Vin = 12 V, 1.5 VDDQ/20 A

87.3%

VTT Output

VTT output voltage

VTTREF

V

For DDR2(0.9 VTT) and DDR3(0.75 VTT)

–2

2

A

VTT output current

For DDR3L(0.675 VTT) and DDR4(0.6 VTT)

–1.5

1.5

A

–40

40

mV

VTT output tolerance to VTTREF

–40

40

mV

VTTREF Output

VTTREF output voltage

VDDQSNS/2

V

VTTREF output current

–10

10

mA

3

SLUU526

– August 2011

Using the TPS51916EVM-746 Complete DDR2, DDR3, DDR3L, and DDR4

Memory Power Solution Synchronous Buck Controller, 2-A LDO, Buffered

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Reference

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© 2011, Texas Instruments Incorporated