PM6686 STMicroelectronics, PM6686 Datasheet - Page 8

• Manufacturer Part Number: PM6686
• Description: Dual Step-down Controller With Adjustable Voltages, Adjustable Ldo And Auxiliary Charge Pump Controller For Notebook
• Manufacturer: STMicroelectronics

Pin settings
8/50
Table 2.
N°
10
11
12
13
14
15
16
17
18
19
7
8
9
LDOREFIN
LDO_SW
PHASE1
HGATE1
LGATE1
BOOT1
PVCC
OUT1
ILIM1
LDO
PG1
EN1
FB1
Pin
Pin descriptions (continued)
Linear regulator output. It can provide up to 100 mA peak current. The LDO
regulates at 5 V If LDOREFIN is connected to GND. When the LDO is set at
5 V and LDO_SW is within 5 V switchover threshold, the internal regulator
shuts down and the LDO output pin is connected to LDO_SW through a
0.8 Ω switch. The LDO regulates at 3.3 V if LDOREFIN is connected to
VCC. When the LDO is set at 3.3 V and LDO_SW is within 3.3 V switchover
threshold, the internal regulator shuts down and the LDO output pin is
connected to LDO_SW through a 1.1 Ω switch. Bypass LDO output to GND
with a minimum of 4.7 µF ceramic capacitor.
Feedback of the adjustable linear regulator. Connect LDOREFIN to GND for
fixed 5 V operation. Connect LDOREFIN to VCC for fixed 3.3 V operation.
LDOREFIN can be used to program LDO output voltage from 0.7 V to 4.5 V:
LDO output is two times the voltage of LDOREFIN. The switchover function
is disabled in adjustable mode.
Source of the switchover connection. LDO_SW is the switchover source
voltage for the LDO when LDOREFIN is connected to GND or VCC.
Connect LDO_SW to 5 V if LDOREFIN is tied to GND. Connect LDO_SW to
3.3 V if LDOREFIN is tied to VCC.
Output voltage sense for the switching section 1.This pin must be directly
connected to the output voltage of the switching section. It provides also the
feedback for the switching section 1 when FB1 is tied to GND/VCC.
Feedback input for the switching section 1:
– If this pin is connected to GND, OUT1 operates at 5 V
– If this pin is connected to VCC, OUT1 operates at 1.5 V
– This pin is connected to a resistive voltage-divider from OUT1 to GND to
Positive current sense input for the switching section 1. It is possible to set a
threshold voltage that is compared with 1/10
during the off time.
Power Good output signal for the section 1. This pin is an open drain output
and It is pulled down when the output of the switching section 1 is out of
+/- 10% of its nominal value.
Enable input for the switching section 1.
– If EN1 < 0.8 V the switching section OUT1 is turned off and all faults are
– If EN1 > 2.4 V the switching section OUT1 is turned on.
– If EN1 is connected to VREF2, the switching section OUT1 turns on after
High-side gate driver output for section 1.
Switch node connection and return path for the high-side driver for the
section 1.It is also used as positive and negative current sense input.
Bootstrap capacitor connection for the switching section 1. It supplies the
high-side gate driver.
Low-side gate driver output for the section 1.
5 V low-side gate drivers supply voltage input. Bypass to PGND with a 1 μF
capacitor.
adjust the output voltage from 0.7 V to 5.5 V.
cleared.
the switching section OUT2 reaches regulation.
Doc ID 15281 Rev 4
Function
th
of the GND-PHASE1 drop
PM6686