All trademarks are the property of their respective owners.
The TPS7H4002-SP is a radiation hardened, 3-V to 5.5-V, 3-A synchronous step-down converter with integrated high-side and low-side MOSFETs. High efficiency and efficient usage of space are achieved through low resistance MOSFETs and a current mode control implementation.
The EVM is configured in a default state to accept a 5-V input but can be modified to disable or change the undervoltage lock out (UVLO) protection, allowing for any input voltage from 3 V to 5.5 V. The EVM is also configured for a 2.5-V output at a maximum peak output current of 3 A. Again, the regulated output voltage can be modified by changing one resistor on the board. The TSP7H4002-SP has a dedicated soft start, enable, and power good pins providing design flexibility to meet specific application requirements.
Table 2-1 describes the default configuration of the TPS7H4002EVM-CVAL listing the external components that define the converter design.
Parameter | Specifications | Description |
---|---|---|
Input power supply | 5 V | Bound by UVLO enable circuit (R13, R15) |
Regulated output voltage |
2.5 V |
R7 (RTOP) = 10 kΩ, R5 (RBOTTOM) = 4.7 kΩ |
LOUT |
2.2 µH |
Chosen to meet inductor ripple current of 40% (Kind = 0.4) |
COUT | 330 µF | Chosen for (1) ESR = 6 mΩ to set output voltage
ripple; (2) value used during single event effects testing ensuring regulation maintained with single event upset to switching |
Output current | 0 to 3 A | By design |
Switching frequency | 500 kHz | Set by R10 (RT) = 95.3 kΩ |
Soft start time constant | ≈ 3.2 ms | Set by C1 (Css) = 10 nF |
UVLO enable rising | ≈ 4.432 V | Set by R13 = 10 kΩ and R15 = 3.4 kΩ |
UVLO enable falling | ≈ 4.284 V | Set by R13 = 10 kΩ and R15 = 3.4 kΩ |
Loop bandwidth | ≈ 30 kHz | Set by operational transconductance amplifier (OTA) compensation circuit: R14 (RCOMP) = 11.8 kΩ, C14 (CCOMP) = 22 nF, C6 (CHF) = 22 pF |
Loop phase margin | ≈ 60° | |
Gain margin | ≈ –25 dB |