EP53A7LQI Datasheet, PDF (11/19 Pages) Altera Corporation – 1A PowerSoC Light Load Mode Buck Regulator with Integrated Inductor

Detailed Description
Functional Overview
The EP53A7xQI requires only 2 small MLCC
capacitors and an 0201 resistor for a complete
DC-DC converter solution. The device
integrates MOSFET switches, PWM controller,
Gate-drive, compensation, and inductor into a
tiny 3mm x 3mm x 1.1mm QFN package.
Advanced package design, along with the high
level of integration, provides very low output
ripple and noise. The EP53A7xQI uses
voltage mode control for high noise immunity
and load matching to advanced ≤90nm loads.
A 3-pin VID allows the user to choose from one
of 8 output voltage settings. The EP53A7xQI
comes with two VID output voltage ranges.
The EP53A7HQI provides V_OUT settings from
1.8V to 3.3V, the EP53A7LQI provides VID
settings from 0.8V to 1.5V, and also has an
external resistor divider option to program
output setting over the 0.6V to V_IN-0.5V range.
The EP53A7xQI provides the industry’s highest
power density of any 1A DCDC converter
solution.
The key enabler of this revolutionary
integration is Altera Enpirion’s proprietary
power MOSFET technology. The advanced
MOSFET switches are implemented in deep-
submicron CMOS to supply very low switching
loss at high switching frequencies and to allow
a high level of integration. The semiconductor
process allows seamless integration of all
switching, control, and compensation circuitry.
The proprietary magnetics design provides
high-density/high-value magnetics in a very
small footprint. Altera Enpirion magnetics are
carefully matched to the control and
compensation circuitry yielding an optimal
solution with assured performance over the
entire operating range.
Protection features include under-voltage lock-
out (UVLO), over-current protection (OCP),
short circuit protection, and thermal overload
protection.
EP53A7LQI/EP53A7HQI
Integrated Inductor
The EP53A7xQI utilizes a proprietary low loss
integrated inductor. The integration of the
inductor greatly simplifies the power supply
design process. The integrated inductor
provides the optimal solution to the complexity,
output ripple, and noise that plague low power
DCDC converter design.
Voltage Mode Control
The EP53A7xQI utilizes an integrated type III
compensation network. Voltage mode control
is inherently impedance matched to the sub
90nm process technology that is used in
today’s advanced ICs. Voltage mode control
also provides a high degree of noise immunity
at light load currents so that low ripple and high
accuracy are maintained over the entire load
range. The very high switching frequency
allows for a very wide control loop bandwidth
and hence excellent transient performance.
Light Load Mode (LLM) Operation
The EP53A7xQI uses a proprietary light load
mode to provide high efficiency in the low load
operating condition. When the LLM pin is high,
the device is in automatic LLM/PWM mode.
When the LLM pin is low, the device is in PWM
mode. In automatic LLM/PWM mode, when a
light load condition is detected, the device will
(1) step V_OUT up by approximately 1.5% above
the nominal operating output voltage setting,
V_NOM, and then (2) shut down unnecessary
circuitry, and (3) monitor V_OUT. When V_OUT falls
below V_NOM, the device will repeat (1), (2), and
(3). The voltage step up, or pre-positioning,
improves transient droop when a load transient
causes a transition from LLM mode to PWM
mode. If a load transient occurs, causing V_OUT
to fall below the threshold V_MIN, the device will
exit LLM operation and begin normal PWM
operation. Figure 6 demonstrates V_OUT
behavior during transition into and out of LLM
operation.
01543
11
October 11, 2013
www.altera.com/enpirion
Rev D