EVALPM6680 STMicroelectronics, EVALPM6680 Datasheet - Page 30

• Manufacturer Part Number: EVALPM6680
• Description: BOARD EVALUATION FOR PM6680
• Manufacturer: STMicroelectronics

Specifications of EVALPM6680

• Mfg Application Notes: PM6680 Eval Kit, AN2566 App Note
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 3, Non-Isolated
• Power - Output: 13.25W
• Voltage - Output: 1.05V, 1.5V, 5V
• Current - Output: 5A, 5A, 100mA
• Voltage - Input: 6 ~ 28V
• Regulator Topology: Buck
• Frequency - Switching: 200kHz, 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: PM6680
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6241

Device description
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Internal linear regulator
The PM6680 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
100mA. Bypass LDO5 output with a minimum 1 µF ceramic capacitor and a 4,7 µF tantalum
capacitor ( ESR 2 Ω). If the 5 V output goes below 4 V, the system detects a fault condition
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-switch over 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 5V supply.
LDO5 regulator turns off and LDO5 is supplied externally. If V5SW is connected to ground,
the internal 5V regulator is always on and supplies LDO5 output.
Table 7.
Power up sequencing and operative modes
Let's consider SHDN, EN1 and EN2 low at the beginning. The battery voltage is applied as
input voltage. The device is in shutdown mode.
When the SHDN pin voltage is above the shutdown device on threshold (1.5 V typ.), the
controller begins the power-up sequence. All the latched faults are cleared. LDO5
undervoltage control is blanked for 4 ms and the internal regulator LDO5 turns on. If the
LDO5 output is above the UVLO threshold after this time, the device enters in standby
mode. The switching outputs are kept to ground by turning on the low side MOSFETs.
When EN1 and EN2 pins are forced high the switching sections begin their soft start
sequence.
Table 8.
Switching 5V
External 5V
Shutdown
Standby
supply
V5SW
output
GND
Mode
Run
V5SW multifunction pin
Operatives modes
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
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.
SHDN is high,
EN1/EN2 pins are high
Both EN1/EN2 pins are low
and SHDN pin is high
SHDN is low
Conditions
Switching regulators are enabled; internal linear
regulators outputs are enabled.
Internal Linear regulators active (LDO5 is always on).
In Standby mode LGATE1/LGATE2 pins are forced
high while HGATE1/HGATE2 pins are forced low.
All circuits off.
Description
Description
PM6680