Overview

The TPS5430 (packaged in 8-pin SO PowerPAD TPS5430DDA) is a 3.0 A3.0\text{ A} continuous (4.0 A4.0\text{ A} peak) step-down (buck) DC-DC converter from Texas Instruments' Swift™ family. Featuring an integrated 110 mΩ110\text{ m}\Omega high-side N-channel MOSFET switch, it operates over a wide input voltage range from 5.5 V5.5\text{ V} to 36.0 V36.0\text{ V} and regulates output down to 1.221 V1.221\text{ V}.

With a fixed internal switching frequency of 500 kHz500\text{ kHz}, the TPS5430 provides high power density and fast transient response with minimal external component size, serving as a high-performance alternative to legacy 150kHz regulators like the LM2596.

Quick reference

Regulator TypeHigh-Efficiency Step-Down (Buck) DC-DC Converter
PackageSO PowerPAD-8 (DDA / 8-Pin SOIC with Thermal Pad)
Input Voltage Range (VINV_{IN})5.5 V5.5\text{ V} to 36.0 V36.0\text{ V} DC
Output Voltage Range (VOUTV_{OUT})1.221 V1.221\text{ V} to 32.0 V32.0\text{ V} DC (Adjustable)
Continuous Output Current (IOUTI_{OUT})Up to 3.0 A3.0\text{ A} (4.0 A4.0\text{ A} peak current)
Switching Frequency500 kHz500\text{ kHz} fixed internal clock
Conversion EfficiencyUp to 95%95\%
FeaturesInternal slope compensation, thermal shutdown, enable threshold

Pinout (SO PowerPAD-8 Package)

text
        ┌─────────────┐
   BOOT ─│ 1         8 │─ PH
     NC ─│ 2         7 │─ VIN
     NC ─│ 3    EP   6 │─ GND
 VSENSE ─│ 4         5 │─ ENA
        └─────────────┘
PinNameDescription
1BOOTBootstrap cap connection to PH (0.01 μF0.01\ \mu\text{F} / 10nF cap) for high-side gate drive
2NCNo internal connection
3NCNo internal connection
4VSENSEFeedback voltage sense input pin (1.221V1.221\text{V} internal reference)
5ENAEnable input (>1.3V enables converter, <0.5V disables, floating = enabled)
6GNDGround reference (internally connected to thermal PowerPAD)
7VINUnregulated DC power supply input (+5.5V to +36V DC)
8PHPhase / Switch node output connected to internal MOSFET drain

Specifications

ParameterSymbolMinTypMaxUnitConditions
Input Voltage RangeVINV_{IN}5.512 / 2436VOperating range
Feedback Reference VoltageVREFV_{REF}1.1971.2211.245VTJ=−40∘C…125∘CT_J = -40^\circ\text{C} \dots 125^\circ\text{C}
Continuous Output CurrentIOUTI_{OUT}—3.0—AVIN=12V,VOUT=5VV_{IN} = 12\text{V}, V_{OUT} = 5\text{V}
Switch On-ResistanceRDS(ON)R_{DS(ON)}—110180mΩ\text{m}\OmegaVBOOT−VPH=6VV_{BOOT} - V_{PH} = 6\text{V}
Switching FrequencyfSWf_{SW}400500600kHzInternal oscillator
Quiescent CurrentIQI_Q—3.04.4mANon-switching state
Shutdown CurrentISDI_{SD}—1840μA\mu\text{A}VENA=0VV_{ENA} = 0\text{V}

Typical Application Circuit

text
       +V_IN (5.5V - 36V DC Input)
          │
       [Pin 7: VIN]
        TPS5430DDA ──── [Pin 8: PH] ──── [ 15µH Inductor ] ───┬─── +V_OUT Regulated DC Output
          │                                  │                │
       [Pin 6: GND]               [B340A Schottky Diode]   [ R1 = 10kΩ ]
          │                                  │                │
         GND ────────────────────────────────┴────────────────┼─── [Pin 4: VSENSE]
                                                              │
                                                            [ R2 ]
                                                              │
                                                             GND

VOUT=1.221V×(1+R1R2)V_{OUT} = 1.221\text{V} \times \left( 1 + \frac{R_1}{R_2} \right)

Common mistakes

  • Failing to solder the exposed PowerPAD: The bottom thermal pad of the SO PowerPAD-8 package must be soldered directly to a PCB ground plane with thermal vias. Failure to do so reduces thermal dissipation drastically, triggering thermal shutdown under load.
  • Improper Bootstrap capacitor voltage rating: A 10 nF10\text{ nF} ceramic capacitor is required between BOOT and PH. Using a capacitor with low voltage rating or wrong dielectric (use X7R/X5R) can fail high-side gate driving.

Notes

  • TPS5430 vs LM2596: The TPS5430 operates at 500 kHz500\text{ kHz} (3x faster than LM2596's 150 kHz150\text{ kHz}), allowing much smaller 15 μH15\ \mu\text{H} inductors while handling up to 36V inputs.

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