L6725_07 STMICROELECTRONICS [STMicroelectronics], L6725_07 Datasheet - Page 10

• Manufacturer Part Number: L6725_07
• Description: Voltage mode PWM controller with bootstrap anti-discharging system
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6725 - L6725A
5
5.1
5.2
Device description
The controller provides complete control logic and protection for flexible and cost-effective DC-
DC converters. It is designed to drive N-Channel MOSFETs in a synchronous rectified buck
topology. The output voltage of the converter can be precisely regulated down to 600mV with a
maximum tolerance of ±0.8%, when the internal reference is used. The device allows also
using an external reference (0V to 2.5V) for the regulation. The device provides voltage-mode
control. The switching frequency can be set at two different values: 250KHz or 500KHz. The
error amplifier features a 10MHz gain-bandwidth-product and 5V/µs slew-rate that permits to
realize high converter bandwidth for fast transient response. The PWM duty cycle can range
from 0% to 100%. The device protects against over current conditions providing a constant-
current-protection during the soft-start phase and entering in HICCUP mode in all the other
conditions. The device monitors the current by using the R
side MOSFET(s), eliminating the need for a current sensing resistor and guaranteeing an
effective over-current-protection in all the application conditions. Other features are over-
voltage-protection and thermal shutdown. The device is available in SO16N package.
Oscillator
The switching frequency can be fixed to two values: 250KHz or 500KHz by setting the proper
voltage at the EAREF pin (see
reference).
Internal LDO
An internal LDO supplies the internal circuitry of the device. The input of this stage is the V
pin and the output (5V) is the V
voltage to V
Figure
recharge of the bootstrap capacitor.
3. V
CCDR
CCDR
pin must be filtered with a 1uF capacitor to sustain the internal LDO during the
. In this case V
Table 4.
CCDR
CC
and V
pin. The LDO can be by-passed, providing directly a 5V
Pins function and section 4.3 Internal and external
CCDR
pins must be shorted together as shown in
DS(ON)
of both the high-side and low-
Device description
10/32
CC