PM6681A STMicroelectronics, PM6681A Datasheet - Page 6

• Manufacturer Part Number: PM6681A
• Description: Dual synchronous step down controller with adjustable LDO
• Manufacturer: STMicroelectronics

Pin settings
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Table 2.
N°
10
11
12
13
14
15
16
17
4
5
6
7
8
9
CSENSE2
PHASE2
HGATE2
LGATE2
LGATE1
LDO FB
BOOT2
PGND
SHDN
V5SW
OUT2
LDO
EN2
FB2
Pin
Pin functions (continued)
Enable input for the switching section 2.
– The section 2 is enabled applying a voltage greater than 2.4 V to this pin.
– The section 2 is disabled applying a voltage lower than 0.8 V.
When the section is disabled the high side gate driver goes low and Low
Side gate driver goes high. If both EN1 and EN2 pins are low and SHDN pin
is high the device enters in standby mode.
Shutdown control input.
– The device switch off if the SHDN voltage is lower than the device off
– The device switch on if the SHDN voltage is greater than the device on
The SHDN pin can be connected to the battery through a voltage divider to
program an undervoltage lockout. In shutdown mode, the gate drivers of the
two switching sections are in high impedance (high-Z).
Feedback input for the switching section 2 This pin is connected to a
resistive voltage-divider from OUT2 to PGND to adjust the output voltage
from 0.9 V to 3.3 V.
Adjustable internal regulator output. It can be set from 0.9 V to 3.3 V.
LDO pin can provide a 100 mA peak current.
Output voltage sense for the switching section 2. This pin must be directly
connected to the output voltage of the switching section.
Bootstrap capacitor connection for the switching section 2. It supplies the
high-side gate driver.
High-side gate driver output for section 2. This is the floating gate driver
output.
Switch node connection and return path for the high side driver for the
section 2. It is also used as negative current sense input.
Positive current sense input for the switching section 2. This pin must be
connected through a resistor to the drain of the synchronous rectifier
(R
supply controller.
Low-side gate driver output for the section 2.
Power ground. This pin must be connected to the power ground plan of the
power supply.
Low-side gate driver output for the section 1.
Feedback input for the adjustable internal linear regulator. This pin is
connected to a resistive voltage-divider from LDO to SGND to adjust the
output voltage from 0.9 V to 3.3 V.
Internal 5 V regulator bypass connection.
– If V5SW is connected to OUT5 (or to an external 5 V supply) and V5SW is
If V5SW is connected to GND, the LDO5 linear regulator is always on if the
device is not in shutdown mode.
threshold (shutdown mode)
threshold.
greater than 4.9 V, the LDO5 regulator shuts down and the LDO5 pin is
directly connected to OUT5 through a 3 W (max) switch.
DS(on)
sensing) to obtain a positive current limit threshold for the power
Function
PM6681A