MIC68400-2.5YML TR Micrel Inc, MIC68400-2.5YML TR Datasheet - Page 14

• Manufacturer Part Number: MIC68400-2.5YML TR
• Description: IC REG LDO SEQ 4A 2.5V 16-MLF
• Manufacturer: Micrel Inc

Specifications of MIC68400-2.5YML TR

• Regulator Topology: Positive Fixed
• Voltage - Output: 2.5V
• Voltage - Input: Up to 5.5V
• Voltage - Dropout (typical): 0.36V @ 4A
• Number Of Regulators: 1
• Current - Output: 3A
• Current - Limit (min): 4A
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-MLF®, QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MIC68400-2.5YMLTR; MIC68400-2.5YMLTR

Ratiometric Tracking
Ratiometric tracking allows independent ramping
speeds for both regulators so that the regulation
voltage is reached at the same time. This is
accomplished by adding a resistor divider between the
Master output pin and the Slave RC pin. The divider
should be scaled such that the Slave RC pin reaches
or exceeds the target output voltage of the Slave as
the Master reaches its target voltage.
Final Note on Tracking
The MIC68400 does not fully shutdown until the output load is discharged to near zero. If RC is driven from an
external source in a tracking configuration, and the external source does not go to zero on shutdown it may prevent
complete shutdown of the MIC68400. This will cause no damage, but some Q current will remain and may cause
concern in battery operated portable equipment. Also, when RC is driven in tracking mode, pulling EN low will not
cause the output to drop. Maintaining low EN in tracking mode simply means that the MIC68400 will shutdown when
the tracking voltage gets near zero. In no case can the MIC68400 enter the tracking mode unless EN is pulled high.
Micrel, Inc.
August 2009
Fixed Voltage Devices
14
Ratiometric tracking may be used with adjustable
parts by simply connecting the RC pins of the Master
and Slave. Use a single RC capacitor of twice the
normal value (since twice the current is injected into
the single RC cap). Alternatively, fixed parts may use
ratiometric tracking in a manner similar to adjustable
normal tracking, with the tracking divider changed to
the same resistor ratio driving the Master Adj/Sns pin.
Adjustable Voltage Devices
M9999-081809-C
MIC68400