1 Features

• Radiation performance:

– Radiation-hardness-assured up to

TID 100 krad(Si)

– SEL, SEB, and SEGR immune to

LET = 75 MeV-cm2/mg

– SET and SEFI characterized up to

LET = 75 MeV-cm2/mg

• Peak efficiency: 96.9% (VO = 2.5 V)

• Integrated 50-mΩ and 35-mΩ MOSFETs

• Power rail: 3 to 5.5 V on VIN

• 3-A maximum output current

• Flexible switching frequency options:

– 100-kHz to 1-MHz adjustable internal oscillator

– External sync capability: 100 kHz to 1 MHz

– SYNC pin can be configured as a 500-kHz

output for primary-secondary applications

• 0.807-V ±1.5% voltage reference over

temperature, radiation, and line and load

regulation

• Monotonic start-up into prebiased outputs

• Adjustable soft start through external capacitor

• Input enable and power-good output for power

sequencing

• Power good output monitor for undervoltage and

overvoltage

• Adjustable input undervoltage lockout (UVLO)

• 20-pin ultra-small, thermally-enhanced ceramic

flatpack package (HKH) for space applications

2 Applications

• Space satellite point of load supply for FPGAs,

microcontrollers, data converters, and ASICs

• Communications payload

• Optical imaging payload

3 Description

The TPS7H4002-SP is a radiation hardened, 5.5-

V, 3-A synchronous step-down converter, which is

optimized for small designs through high efficiency

and by integrating the high-side and low-side

MOSFETs. Further space savings are achieved

through current mode control, which reduces

component count, and a high switching frequency,

which reduces the inductor footprint.

The output voltage startup ramp is controlled by the

SS/TR pin which allows operation as either a stand

alone power supply or in tracking situations. Power

sequencing is also possible by correctly configuring

the enable and the open drain power good pins. In

addition, the TPS7H4002-SP can be configured in

primary-secondary mode for parallel operation.

Cycle-by-cycle current limiting on the high-side

FET protects the device in overload situations and

is enhanced by a low-side sourcing current limit

which prevents current runaway. There is also a

low-side sinking current limit which turns off the

low-side MOSFET to prevent excessive reverse

current. Thermal shutdown disables the part when die

temperature exceeds thermal limit.