L6725A STMicroelectronics, L6725A Datasheet - Page 6

• Manufacturer Part Number: L6725A
• Description: IC PWM CTLR VOLTAGE MODE SO-16N
• Manufacturer: STMicroelectronics

Specifications of L6725A

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 550kHz
• Duty Cycle: 100%
• Voltage - Supply: 4.5 V ~ 18 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-SOIC (3.9mm Width)
• Frequency-max: 550kHz
• Output Voltage: 0.603 V
• Input Voltage: 1.8 V to 18 V
• Switching Frequency: 500 KHz
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Package: SO16N
• For Use With: 497-5867 - EVAL BOARD 20A 250KHZ L6725497-5500 - EVAL BOARD FOR L6725
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Pin connections and functions
6/32
3
Figure 2.
Table 4.
Pin n°
1
2
3
4
Pin connections and functions
Pins connection (top view)
Pin functions
SS/INH
EAREF
COMP
Name
OCL
This pin is connected to the error amplifier output and is used to compensate the
voltage control feedback loop.
The soft-start time is programmed connecting an external capacitor from this pin to
GND. The internal current generator forces a current of 10µA through the capacitor.
When the voltage at this pin is lower than 0.5V the device is disabled.
By setting the voltage at this pin is possible to select the internal/external reference
and the switching frequency:
V
V
V
An internal clamp limits the maximum V
analog value present at this pin at the start-up when V
A resistor connected from this pin to ground sets the valley- current-limit. The valley
current is sensed through the low-side MOSFET(s). The internal current generator
sources a current of 100µA (I
(R
COMP
SS/INH
EAREF
HGATE
PHASE
EAREF
EAREF
EAREF
BOOT
OCH
OCL
OCL
). The over-current threshold is given by the following equation:
= 80% - 95% of V
= 95% - 100% of V
0-80% of V
8
7
1
2
3
4
5
6
CCDR
SO16N
-> External Reference/F
CCDR
CCDR
OCL
I
VALLEY
15
16
14
13
12
11
10
-> V
9
->V
) from this pin to ground through the external resistor
REF
REF
Function
EAREF
= 0.6V/F
=
= 0.6V/F
FB
SGND
SYNCH/NC
PGOOD/NC
VCC
VCCDR
LGATE
PGND
I
2
OCL
⋅
R
at 2.5V (typ.). The device captures the
DSonLS
⋅
R
SW
SW
SW
OCL
= 500KHz
= 250KHz
= 250KHz
CC
meets the UVLO threshold.
L6725 - L6725A