MIC68200 Datasheet, PDF (1/15 Pages) Micrel Semiconductor – 2A Sequencing LDO with Tracking and Ramp Control

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
• 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 500mV 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
• 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 [phone] • fax + 1 [phone] • http://www.micrel.com
July 2006
M9999-071206
[phone]