ER3125QI Datasheet, PDF (1/30 Pages) Altera Corporation – MOSFET for Synchronous Buck or Boost Buck Converter

ER3125QI
Enpirion^® Power Datasheet
ER3125QI 2.5 A Regulator with Integrated High-Side
MOSFET for Synchronous Buck or Boost Buck Converter
Datasheet
The ER3125QI is a 36V, 2.5A synchronous buck or boost buck
controller with a high-side MOSFET and low-side driver integrated.
In buck mode, the ER3125QI supports a wide input range of 3V to
36V. In boost-buck mode, the input range can be extended down to
2.5V and output regulation can be maintained when V_PVIN drops
below V_OUT, enabling sensitive electronics to remain on in low input
voltage conditions.
The ER3125QI has a flexible selection of operation modes of
forced PWM mode and LLM mode. In LLM mode, the
quiescent input current is as low as 180µA (AVIN connected to
V_OUT). The load boundary between LLM and PWM can be
programmed to cover wide applications.
The low-side driver can be either used to drive an external low-
side MOSFET for a synchronous buck, or left unused for a
standard non-synchronous buck. The low-side driver can also be
used to drive a boost converter as a pre-regulator followed by a
buck controlled by the same IC, which greatly expands the
operating input voltage range down to 2.5V or lower (Refer to
“Typical Application Schematic III - Boost Buck Converter” on
page 4).
The ER3125QI offers the most robust current protections. It uses
peak current mode control with cycle-by-cycle current limiting.
It is implemented with frequency foldback under current limit
condition; besides that, the hiccup overcurrent mode is also
implemented to guarantee reliable operations under short
circuit conditions.
The ER3125QI has comprehensive protections against various
faults including overvoltage and over-temperature protections,
etc.
POK
LLM
PVIN
AVIN
AVINO _ER3125QI
SW
RCLX
V_PVIN
BOOST
FSW
AGND
FIGURE 1. TYPICAL APPLICATION
Features
• Buck mode: input voltage range 3V to 36V (refer to “Input
Voltage” on page 16 for more details)
• Boost mode expands operating input voltage lower than 2.5V
(refer to “Input Voltage” on page 16 for more details)
• Selectable forced PWM mode or LLM mode
• 300µA IC quiescent current (LLM, no load); 180µA input
quiescent current (LLM, no load, V_OUT tied to AVIN)
• Less than 5µA (MAX) shutdown input current (IC disabled)
• Operational topologies
- Synchronous buck
- Non-synchronous buck
- Two-stage boost buck
- Non-inverting single inductor buck boost
• Programmable frequency from 200kHz to 2.2MHz and
frequency synchronization capability
• ±1% tight voltage regulation accuracy
• Reliable overcurrent protection
- Temperature compensated current sense
- Cycle-by-cycle current limiting with frequency foldback
- Hiccup mode for worst case short condition
• 20 Ld 4x4 QFN package
• Pb-free (RoHS compliant)
Applications
• FPGA Applications
• General purpose
• 24V bus power
• Battery power
• Point of load
• Embedded processor and I/O supplies
100
95
6V V_PVIN
90
85
12V V_PVIN
80
75
36V V_PVIN
24V V_PVIN
70
65
60
55
50
0.1m
1m
10m
100m
1.0 2.5
LOAD CURRENT (A)
FIGURE 2. EFFICIENCY, SYNCHRONOUS BUCK, LLM MODE, V_OUT 5V, T_A =
+25°C
101 Innovation Drive
San Jose, CA 95134
www.altera.com
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ISO
9001:2008
Registered
May 2014 Altera Corporation
10040
May 28, 2014
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