STEVAL-ISA053V2 STMicroelectronics, STEVAL-ISA053V2 Datasheet - Page 27

• Manufacturer Part Number: STEVAL-ISA053V2
• Description: BOARD EVALUATION FOR PM6680A
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of STEVAL-ISA053V2

• Design Resources: STEVAL-ISA053V2 Gerber Files PM6680A Eval Kit Schematic STEVAL-ISA053V2 Bill of Material
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 3, Non-Isolated
• Voltage - Output: 1.8V, 3.3V, 5V
• Current - Output: 2.5A, 2.5A, 100mA
• Voltage - Input: 6 ~ 28V
• Regulator Topology: Buck
• Frequency - Switching: 200kHz, 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: PM6680A
• Input Voltage: 6 V to 36 V
• Output Voltage: 5 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PM6680A
• Other names: 497-6379

PM6680A
7.9
7.10
Reference voltage and bandgap
The 1.237 V (typ.) internal bandgap voltage is accurate to ±1 % over the temperature range.
It is externally available (VREF pin) and can supply up to ± 100 µA and can be used as a
voltage threshold for the multifunction pins FSEL and SKIP to select the appropriate working
mode. Bypass VREF to ground with a 100 nF minimum capacitor.
If VREF goes below 0.87 V (typ.) , the system detects a fault condition and all the circuitry is
turned off. A toggle on the input voltage (power on reset) or a toggle on SHDN pin is
necessary to restart the device.
An internal divider of the bandgap provides a voltage reference Vr of 0.9 V. This voltage is
used as reference for the linear and the switching regulators outputs. The overvoltage
protection, the undervoltage protection and the power good signals are referred to Vr.
Internal linear regulator
The PM6680A has an internal linear regulator providing 5 V (LDO5) at ± 2 % accuracy. High
side drivers, low side drivers and most of internal circuitry are supplied by LDO5 output
through VCC pin (an external RC filter may be applied between LDO5 and VCC). The linear
regulator can provide an average output current of 50 mA and a peak output current of 100
mA. Bypass LDO5 output with a minimum 1µF ceramic capacitor and a 4,7 µF tantalum
capacitor ( ESR
and all the circuitry is turned off. A power on reset or a toggle on SHDN pin is necessary to
restart the device.
V5SW pin allows to keep the 5 V linear regulator always active or to enable the internal
bootstrap-switchover function: if the 5 V switching output is connected to V5SW, when the
voltage on V5SW pin is above 4.8 V, an internal 3.0 Ω max p-channel MOSFET switch
connects V5SW pin to LDO5 pin and simultaneously LDO5 shuts down. This configuration
allows to achieve higher efficiency. V5SW can be connected also to an external 5 V supply.
LDO5 regulator turns off and LDO5 is supplied externally. If V5SW is connected to ground,
the internal 5 V regulator is always on and supplies LDO5 output
Table 7.
Switching 5 V
External 5 V
supply
V5SW
output
GND
V5SW multifunction pin
The 5 V linear regulator is always turned on and supplies LDO5 output.
The 5 V linear regulator is turned off when the voltage on V5SW is above 4.8 V and
the LDO5 output is supplied by the switching 5 V output.
The 5 V linear regulator is turned off when the voltage on V5SW is above 4.8 V and
LDO5 output is supplied by the external 5 V.
≥
2 Ω ). If the 5 V output goes below 4 V, the system detects a fault condition
Description
Device description
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