EN2340QI Datasheet, PDF (10/23 Pages) Enpirion, Inc. – 204A Voltage Mode Synchronous Buck PWM

Functional Block Diagram
EN2340QI
UVLO
Thermal Limit
Current Limit
S_OUT S_IN
BTMP
PG
Digital I/O
To PLL
PVIN
Linear
Regulator
AVINO
Gate Drive
NC(SW)
VOUT
FADJ
(-)
PWM
Comp
(+)
PLL/Sawtooth
Generator
Compensation
Network
BGND
PGND
VDDB
EAOUT
(-)
Error
VFB
Amp
(+)
Power
SS
Good
POK
Logic
300k
ENABLE
Soft Start
370k
EN2340QI
Voltage Reference Generator
Band Gap
Reference
AVIN
AGND
Figure 4: Functional Block Diagram
Functional Description
Synchronous Buck Converter
The EN2340QI is a highly integrated synchronous,
buck converter with integrated controller, power
MOSFET switches and inductor. The nominal input
voltage (PVIN) range is 4.5V to 14V and can
support up to 4A of continuous output current. The
output voltage is programmed using an external
resistor divider network. The control loop utilizes a
Type IV Voltage-Mode compensation network and
maximizes on a low-noise PWM topology. Much of
the compensation circuitry is internal to the device.
However, a phase lead capacitor is required along
with the output voltage feedback resistor divider to
complete the Type IV compensation network.. The
high switching frequency of the EN2340QI enables
the use of small size input and output filter
capacitors, as well as a wide loop bandwidth within
a small foot print.
Protection Features:
The power supply has the following protection
features:
• Programmable Over-Current Protection
• Thermal Shutdown with Hysteresis.
• Under-Voltage Lockout Protection
Additional Features:
• Switching Frequency Synchronization.
• Programmable Soft-Start
• Power OK Output Monitoring
www.altera.com/enpirion, Page 10
06878
October 9, 2013
Rev E