L6738ATR STMicroelectronics, L6738ATR Datasheet - Page 25

• Manufacturer Part Number: L6738ATR
• Description: IC PWM CTLR 1PH STPDN 16-VFQFPN
• Manufacturer: STMicroelectronics

Specifications of L6738ATR

• Frequency - Max: 220kHz
• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Duty Cycle: 100%
• Voltage - Supply: 5 V ~ 12 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-11012-2

L6738A
Connect output bulk capacitors (C
inductance and resistance associated to the copper trace, also adding extra decoupling
capacitors along the way to the load when this results in being far from the bulk capacitors
bank.
Remote Sense Connection must be routed as parallel nets from the FBG/VSEN pins to the
load in order to avoid the pick-up of any common mode noise. Connecting these pins in
points far from the load causes a non-optimum load regulation, increasing output tolerance.
Locate current reading components close to the device. The PCB traces connecting the
reading point must use dedicated nets, routed as parallel traces in order to avoid the pick-up
of any common mode noise. It's also important, to avoid any offset in the measurement and,
to get a better precision, to connect the traces as close as possible to the sensing elements.
A small filtering capacitor can be added, near the controller, between VOUT and GND, on
the CSN line to allow higher layout flexibility.
Figure 11. Power connections (heavy lines)
Gate traces and phase trace must be sized according to the driver RMS current delivered to
the power MOSFET. The device robustness allows the managing of applications with the
power section far from the controller without losing performance. However, when possible, it
is recommended to minimize the distance between the controller and power section.
Small signal components and connections to critical nodes of the application, as well as
bypass capacitors for the device supply, are also important. Locate the bypass capacitor
(VCC and bootstrap capacitor) and feedback compensation components as close to the
device as practical.
Figure 12. Drivers turn-on and turn-off paths
LS DRIVER
VCCDR
LGATE
GND
L6738
R
GATE
UGATE
PHASE
LGATE
GND
LS MOSFET
R
INT
C
GS
C
GD
Doc ID 18134 Rev 1
OUT
) as near as possible to the load, minimizing parasitic
C
DS
V
C
IN
IN
HS DRIVER
L
PHASE
BOOT
UGATE
C
OUT
R
GATE
Application details
LOAD
HS MOSFET
R
INT
C
GS
C
GD
25/32
C
DS