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LINEAR TECHNOLOGY - LTC2927 Data Sheet User Manual

Summary

The LTC2927 is an advanced single power supply tracking controller designed for managing complex multiple voltage rails in digital systems. It provides reliable, highly configurable power sequencing and accurate ramp-up/ramp-down capabilities, ensuring system stability across different supply states without added loss elements. Ideal for mission-critical applications like microprocessors, DSPs, and FPGAs, this controller allows precise synchronization of supplies at the load point. The comprehensive manual details its core features, electrical characteristics, application examples, and pinout information for seamless integration into power management circuits.

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LTC2927

Single Power Supply Tracking Controller FEATURES DESCRIPTIO

n Flexible Power Supply Tracking The LTC®2927 provides a simple solution to power supply n Tracks Both Up and Down tracking and sequencing requirements. By selecting a few n Power Supply Sequencing resistors, the supply can be confi gured to ramp-up and n Supply Stability is Not Affected ramp-down with differing ramp rates, voltage offsets, or n Low Pin Count time delays relative to other supplies or a master signal. n Controls Single Supply without Series FETs

By forcing current into a feedback node of an independent

n Adjustable Ramp Rate

supply, the LTC2927 causes the output to track a ramp

n Supply Shutdown Output

signal without inserting any pass element losses. Because

n Available in 8-Lead Thin SOT™ and 8-Lead

the current is controlled in an open-loop manner, the

(3mm × 2mm) DFN Packages

LTC2927 does not affect the transient response or stabil- ity of the supply. The compact solution at point of load APPLICATIO minimizes the trace length of the DC/DC circuit sensitive FB node. Furthermore, it presents a high impedance when

n VCORE and VI/O Supply Tracking

power-up is complete, effectively removing it from the

n Microprocessor, DSP and FPGA Supplies

DC/DC circuit.

n Multiple Supply Systems

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. n Point-of-Load Supplies Thin SOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Patents Pending.

TYPICAL APPLICATIO

EARLY VIN Track-Up and Track-Down Waveforms

VCC ON RAMP

0.1μF VIN

100k RAMP

LTC2927

(3.3V) SDO RUN/SS IN 2.5V 1.8V1V/DIV

DC/DC

RAMPBUF

16.5k FB FB = 1.235V OUT 1.8V

TRACK

GND 35.7k13k

2927 TA01b10ms/DIV

EARLY VIN 3.3V 0.1μF

ON RAMP VIN

LTC2927

1V/DIV

SDO RUN/SS IN 1.8V

DC/DC

RAMPBUF

887k FB FB = 0.8V OUT 2.5V

TRACK

GND 412k412k

2927 TA01c10ms/DIV

2927 TA01a

2927fb

Page Summary Contents For LINEAR TECHNOLOGY - LTC2927 Data Sheet User Manual

Page 1 LTC2927 Single Power Supply Tracking Controller FEATURES DESCRIPTIO n Flexible Power Supply Tracking The LTC®2927 provides a simple solution to power supply n Tracks Both Up and Down tracking and sequ...
Page 2 LTC2927 RATI GS (Note 1)ABSOLUTE AXI Supply Voltage (VCC) ................................. –0.3V to 10V Average Current Input Voltages TRACK .............................................................
Page 3 LTC2927 ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. 2.9V < VCC < 5.5V unless o...
Page 4 LTC2927 TYPICAL PERFOR A CE CHARACTERISTICS VRAMPBUF(OL) vs Temperature VRAMPBUF(OH) vs Temperature VON(TH) vs Temperature –50 –25 –50 –25 –50 –25 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) MA...
Page 5 LTC2927 FU CTIO TSOT/DFN Packages PI GND (Pin 4/Pin 5): Device Ground. RAMP (Pin 7/Pin 2): Ramp Buffer Input. The RAMP pin is the input to the voltage buffer whose output drives a resis- TRACK (Pin 5/...
Page 6 LTC2927 APPLICATIO S I FOR ATIO Power Supply Tracking and Sequencing before a block of logic. In this case, the supplies are se- quenced as in Figure 4 where the 2.5V supply ramps up The LTC2927 handl...
Page 7 LTC2927 APPLICATIO S I FOR ATIO pin is mirrored at the FB pin to establish a voltage at the The ON pin can be controlled by a digital I/O pin or it output of the slave supply. The slave output voltage...
Page 8 LTC2927 APPLICATIO S I FOR ATIO EARLY Choose a ramp rate for the slave supply, SS. If the slave VIN 3.3V 0.1μF supply ramps up coincident with the master signal or RONB with a fi xed voltage offset, t...
Page 9 LTC2927 APPLICATIO S I FOR ATIO Coincident Tracking Example MASTER SLAVE2 1V/DIV 1V/DIV SLAVE1 2927 F0910ms/DIV 10ms/DIV Figure 9. Coincident Tracking (from Figure 10) A typical application is shown i...
Page 10 LTC2927 APPLICATIO S I FOR ATIO Ratiometric Tracking Example MASTER SLAVE2 1V/DIV 1V/DIV SLAVE1 2927 F1110ms/DIV 10ms/DIV Figure 11. Ratiometric Tracking (from Figure 12) This example converts the coi...
Page 11 LTC2927 APPLICATIO S I FOR ATIO Offset Tracking Example MASTER SLAVE2 1V/DIV 1V/DIV SLAVE1 2927 F1310ms/DIV 10ms/DIV Figure 13. Offset Tracking (from Figure 14) Converting the circuit in the coinciden...
Page 12 LTC2927 APPLICATIO S I FOR ATIO Supply Sequencing Example MASTER SLAVE2 1V/DIV 1V/DIV SLAVE1 2927 F1510ms/DIV 10ms/DIV Figure 15. Supply Sequencing (from Figure 16) In Figure 15, the slave 1 supply an...
Page 13 LTC2927 APPLICATIO S I FOR ATIO Final Sanity Checks The collection of equations below is useful for identifying unrealizable solutions. For example, if the typical application shown on page 1 As state...
Page 14 LTC2927 APPLICATIO S I FOR ATIO Start-Up Delays Layout Considerations Often power supplies do not start-up immediately when Be sure to place a 0.1μF bypass capacitor as near as pos- their input suppli...
Page 15 LTC2927 PACKAGE DESCRIPTIO DDB Package 8-Lead Plastic DFN (3mm × 2mm) (Reference LTC DWG # 05-08-1702) (2 SIDES) TYP (2 SIDES) 0.675 ±0.05 (2 SIDES) 1.15 ±0.05 PIN 1 BAR (2 SIDES) TOP MARK PIN 1 (SEE ...
Page 16 LTC2927 TYPICAL APPLICATIO High Voltage Supply Application Single Supply Application EARLY EARLY VIN VIN 3.3V 3.3V 0.1μF RONB RONB 138k VCC 138k VCC ON RAMP MASTER ON RAMP MASTER RONA CRAMP RONA CRAMP...

Manual Details

Brand Linear
Pages 16
File Size 264.36 KB
Published June 21, 2026
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Frequently Asked Questions

What kind of tracking does the LTC2927 support?

It tracks both Up and Down tracking, and can be configured to ramp up or ramp down with differing rates or voltage offsets.

How does it manage supply shutdown without loss?

Because current is controlled in an open-loop manner via the FB node, it shuts down without inserting any pass element losses.

Does using the LTC2927 affect circuit stability?

No, its compact point-of-load solution minimizes trace length and does not affect the transient response or stability of the supply.

What is one key feature for multiple supplies?

The device can control single supplies without needing Series FETs, which keeps the current controlled at an open-loop manner.