The TPS54541 device is a 42-V 5-A step-down regulator with an integrated high-side MOSFET. The device survives load dump pulses up to 45 V per ISO 7637. Current mode control provides simple external compensation and flexible component selection. A low-ripple pulse-skip mode reduces the no-load supply current to 152 μA. When the enable pin is pulled low, the shutdown supply current is reduced to 2 μA .
Undervoltage lockout is internally set at 4.3 V but can increase using an external resistor divider at the enable pin. The output voltage startup ramp is controlled by the soft-start pin that can also be configured for sequencing and tracking. An open-drain power-good signal indicates the output is within 93% to 106% of the nominal voltage.
A wide adjustable switching-frequency range allows for optimization of either efficiency or external component size. Cycle-by-cycle current limit, frequency foldback, and thermal shutdown protect internal and external components during an overload condition.
The TPS54541 device is available in a 10-pin 4-mm × 4-mm WSON package.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
TPS54541 | WSON (10) | 4.00 mm × 4.00 mm |
SPACER
SPACER
Changes from B Revision (February 2016) to C Revision
Changes from A Revision (August 2015) to B Revision
Changes from * Revision (October 2013) to A Revision
PIN | I/O | DESCRIPTION | ||
---|---|---|---|---|
NAME | NO. | |||
BOOT | 1 | O | A bootstrap capacitor is required between BOOT and SW. If the voltage on this capacitor is below the minimum required to operate the high-side MOSFET, the gate drive is switched off until the capacitor is refreshed. | |
COMP | 7 | O | Error amplifier output and input to the output switch current (PWM) comparator. Connect frequency compensation components to this pin. | |
EN | 3 | I | Enable pin, with an internal pullup current source. Pull below 1.2 V to disable. Float to enable. Adjust the input undervoltage lockout with two resistors. See the Enable and Adjusting Undervoltage Lockout section. | |
FB | 6 | I | Inverting input of the transconductance (gm) error amplifier. | |
GND | 8 | – | Ground | |
PWRGD | 10 | O | Power Good is an open drain output that asserts low if the output voltage is out of regulation due to thermal shutdown, dropout, over-voltage or EN shut down. | |
RT/CLK | 5 | I | Resistor Timing and External Clock. An internal amplifier holds this pin at a fixed voltage when using an external resistor to ground to set the switching frequency. If the pin is pulled above the PLL upper threshold, a mode change occurs and the pin becomes a synchronization input. The internal amplifier is disabled and the pin is a high impedance clock input to the internal PLL. If clocking edges stop, the internal amplifier is re-enabled and the operating mode returns to resistor frequency programming. | |
SS/TR | 4 | I | Soft-start and Tracking. An external capacitor connected to this pin sets the output rise time. Because the voltage on this pin overrides the internal reference, SS/TR can be used for tracking and sequencing. | |
SW | 9 | O | The source of the internal high-side power MOSFET and switching node of the converter. | |
VIN | 2 | I | Input supply voltage with 4.5-V to 42-V operating range. | |
Thermal Pad | 11 | – | The GND pin must be electrically connected to the exposed pad on the printed circuit board for proper operation. |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | ±2000 | V |
Charged device model (CDM), per JEDEC specification JESD22-C101(2) | ±500 |
MIN | NOM | MAX | UNIT | |||
---|---|---|---|---|---|---|
VVIN | Supply input voltage | 4.5 | 42 | V | ||
VO | Output voltage | 0.8 | 41.1 | V | ||
IO | Output current | 0 | 5 | A | ||
TJ | Operating junction temperature | –40 | 150 | °C |
THERMAL METRIC(1)(2) | TPS54541 | UNIT | |
---|---|---|---|
DPR (WSON) | |||
10 PINS | |||
RθJA | Junction-to-ambient thermal resistance (standard board) | 35.1 | °C/W |
RθJC(top) | Junction-to-case(top) thermal resistance | 34.1 | °C/W |
RθJB | Junction-to-board thermal resistance | 12.3 | °C/W |
ψJT | Junction-to-top characterization parameter | 0.3 | °C/W |
ψJB | Junction-to-board characterization parameter | 12.5 | °C/W |
RθJC(bot) | Junction-to-case(bottom) thermal resistance | 2.2 | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | ||
---|---|---|---|---|---|---|---|
SUPPLY VOLTAGE (VIN PIN) | |||||||
Operating input voltage | 4.5 | 42 | V | ||||
Internal undervoltage lockout threshold | Rising | 4.1 | 4.3 | 4.48 | V | ||
Internal undervoltage lockout threshold hysteresis | 325 | mV | |||||
Shutdown supply current | EN = 0 V, 25°C, 4.5 V ≤ VIN ≤ 42 V | 2.25 | 4.5 | μA | |||
Operating: nonswitching supply current | FB = 0.9 V, TA = 25°C | 152 | 200 | ||||
ENABLE AND UVLO (EN PIN) | |||||||
Enable threshold voltage | No voltage hysteresis, rising and falling | 1.1 | 1.2 | 1.3 | V | ||
Input current | Enable threshold +50 mV | –4.6 | μA | ||||
Enable threshold –50 mV | –0.58 | –1.2 | -1.8 | ||||
Hysteresis current | –2.2 | –3.4 | -4.5 | μA | |||
Enable to COMP active | VIN = 12 V, TA = 25°C | 540 | µs | ||||
VOLTAGE REFERENCE | |||||||
Voltage reference | 0.792 | 0.8 | 0.808 | V | |||
HIGH-SIDE MOSFET | |||||||
On-resistance | VIN = 12 V, BOOT-SW = 6 V | 87 | 185 | mΩ | |||
ERROR AMPLIFIER | |||||||
Input current | 50 | nA | |||||
Error amplifier transconductance (gm) | –2 μA < ICOMP < 2 μA, VCOMP = 1 V | 350 | μS | ||||
Error amplifier transconductance (gm) during soft-start | –2 μA < ICOMP < 2 μA, VCOMP = 1 V, VFB = 0.4 V | 77 | μS | ||||
Error amplifier dc gain | VFB = 0.8 V | 10,000 | V/V | ||||
Min unity gain bandwidth | 2500 | kHz | |||||
Error amplifier source/sink | V(COMP) = 1 V, 100 mV overdrive | ±30 | μA | ||||
COMP to SW current transconductance | 17 | A/V | |||||
CURRENT LIMIT | |||||||
Current limit threshold | All VIN and temperatures, Open Loop(1) | 6.3 | 7.5 | 8.8 | A | ||
All temperatures, VIN = 12 V, Open Loop(1) | 6.3 | 7.5 | 8.3 | ||||
VIN = 12 V, TA = 25°C, Open Loop(1) | 7.1 | 7.5 | 7.9 | ||||
Current limit threshold delay | 60 | ns | |||||
THERMAL SHUTDOWN | |||||||
Thermal shutdown | 176 | °C | |||||
Thermal shutdown hysteresis | 12 | °C | |||||
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN) | |||||||
RT/CLK high threshold | 1.55 | 2 | V | ||||
RT/CLK low threshold | 0.5 | 1.2 | V | ||||
SOFT START AND TRACKING (SS/TR PIN) | |||||||
Charge current | VSS/TR = 0.4 V | 1.7 | µA | ||||
SS/TR-to-FB matching | VSS/TR = 0.4 V | 42 | mV | ||||
SS/TR-to-reference crossover | 98% nominal | 1.16 | V | ||||
SS/TR discharge current (overload) | FB = 0 V, VSS/TR = 0.4 V | 354 | µA | ||||
SS/TR discharge voltage | FB = 0 V | 54 | mV | ||||
POWER GOOD (PWRGD PIN) | |||||||
FB threshold for PWRGD low | FB falling | 90% | |||||
FB threshold for PWRGD high | FB rising | 93% | |||||
FB threshold for PWRGD low | FB rising | 108% | |||||
FB threshold for PWRGD high | FB falling | 106% | |||||
Hysteresis | FB falling | 2.5% | |||||
Output high leakage | VPWRGD = 5.5 V, TA = 25°C | 10 | nA | ||||
On resistance | IPWRGD = 3 mA, VFB < 0.79 V | 45 | Ω | ||||
Minimum VIN for defined output | VPWRGD < 0.5 V, IPWRGD = 100 µA | 0.9 | 2 | V |
MIN | NOM | MAX | UNIT | |||
---|---|---|---|---|---|---|
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN) | ||||||
Minimum CLK input pulse width | 15 | ns | ||||
RT/CLK falling edge to SW rising edge delay – Measured at 500 kHz with RT resistor in series | 55 | ns |
PARAMETER | TEST CONDITIONS | MIN | NOM | MAX | UNIT | |
---|---|---|---|---|---|---|
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN) | ||||||
ƒSW | Switching frequency | RT = 200 kΩ | 450 | 500 | 550 | kHz |
Switching frequency range using RT mode | 100 | 2500 | kHz | |||
Switching frequency range using CLK mode | 160 | 2300 | kHz | |||
PLL lock in time | Measured at 500 kHz | 78 | μs |