MIC68200
2A Sequencing LDO with Tracking
and Ramp Control™
General Description
The MIC68200 is a high peak current LDO regulator
designed specifically for powering applications such
as FPGA core voltages that require high start up
current with lower nominal operating current. Capable
of sourcing 2A of current for start-up, the MIC68200
provides high power from a small MLF
®
leadless
package. The MIC68200 can also implement a variety
of power-up and power-down protocols such as
sequencing, tracking, and ratiometric tracking.
The MIC68200 operates from a wide input range of
1.65V to 5.5V, which includes all of the main supply
voltages commonly available today. It is designed to
drive digital circuits requiring low voltage at high
currents (i.e. PLDs, DSP, microcontroller, etc.). The
MIC68200 incorporates a delay pin (DLY) for control
of power on reset output (POR) at turn-on and power-
down delay at turn-off. In addition there is a ramp
control pin (RC) for either tracking applications or
output voltage slew rate adjustment at turn-on. This is
important in applications where the load is highly
capacitive and in-rush currents can cause supply
voltages to fail and microprocessors or other complex
logic chips to hang up.
Multiple MIC68200s can be daisy chained in two
modes. In tracking mode the output voltage of the
Master drives the RC pin of a Slave so that the Slave
tracks the main regulator during turn-on and turn-off.
In sequencing mode the POR of the Master drives the
enable (EN) of the Slave so that it turns on after the
Master and turns off before (or after) the Master. This
behavior is critical for power-up and power-down
control in multi-output power supplies. The MIC68200
is fully protected offering both thermal and current limit
protection and reverse current protection.
The MIC68200 has a junction temperature range of
–40°C to +125°C and is available in fixed as well as
an adjustable option. The MIC68200 is offered in the
®
tiny 10-pin 3mm x 3mm MLF package.
Features
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Stable with 4.7µF ceramic capacitor
Input voltage range: 1.65V to 5.5V
0.5V reference
+1.0% initial output tolerance
2A maximum output current – peak start up
1A Continuous Operating Current
Tracking on turn-on and turn-off with pin
strapping
Timing Controlled Sequencing On/Off
Programmable Ramp Control for in-rush
current limiting and slew rate control of the
output voltage on Turn-On and Turn-Off
Power-on Reset (POR) supervisor with
programmable delay time
Single Master can control multiple Slave
regulators with tracking output voltages
Tiny 3mm x 3mm MLF
®
package
Maximum dropout (V
IN
– V
OUT
) of 400mV over
temperature at 1A output current
Fixed and Adjustable Output Voltages
Excellent line and load regulation specifications
Logic controlled shutdown
Thermal shutdown and current limit protection
Applications
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FPGA/PLD Power Supply
Networking/Telecom Equipment
Microprocessor Core Voltage
High Efficiency Linear Post Regulator
Sequenced or Tracked Power Supply
Ramp Control is a trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
February 2011
M9999-022311-E
Micrel, Inc.
MIC68200
Pin Configuration
1
2
3
4
5
EP
10
9
8
7
6
10-Pin 3mm × 3mm MLF (ML)
MIC68200-x.xYML (Fixed)
MIC68200YML (Adjustable)
Pin Description
(Pin Numbering may change depending on layout considerations)
3x3 MLF-10
Fixed
1,2
3
4
5
6, EP
7
3x3 MLF-10
Adjustable
1,2
3
4
5
6, EP
7
Pin Name
IN
DLY
RC
EN
GND
POR
Pin Function
Input: Input voltage supply pin. Place a capacitor to ground to
bypass the input supply
Delay: Capacitor to ground sets internal delay timer. Timer delays
power-on reset (POR) output at turn-on and ramp down at turn-off.
Ramp Control: Voltage driven for tracking applications. Capacitor to
ground sets slew rate during start-up.
Enable (Input): CMOS compatible input. Logic high = enable and
logic low = shutdown.
Ground: EP is connected to ground on 3x3 MLF-10L.
Power-on Reset: Open-drain output device indicates when the
output is in regulation. High (open) means device is regulating within
10%. POR onset can be delayed using a single capacitor from Delay
to ground.
Adjustable regulators: Feedback input. Connect to external resistor
voltage divider.
Fixed regulators: Sense pin. Connect to output at load for point-of-
load regulation.
Output Voltage: Output of voltage regulator. Place capacitor to
ground to bypass the output voltage. Minimum load current is 100µA.
Nominal bypass capacitor is 4.7µf ceramic.
8
8
SNS
9, 10
9,10
OUT
February 2011
5
M9999-022311-E
模拟与混合信号
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