TPS2306

DUAL SEQUENCING HOT SWAP POWER MANAGER

SLVS368 − APRIL 2001

1

POST OFFICE BOX 655303

13.6 V)

and Ramp-Down Sequence

Efficiency and Low Voltage Drop

Fault Timer

External NMOS Devices

Mode (40

µA)

The TPS2306 Hot Swap Power Manager (HSPM) IC provides hot-swap control, fault handling and power supply

sequencing of two positive voltage supplies. The TPS2306 operates over a wide supply range allowing single

part inventory for a variety of output voltages.

During the transient period of a live insertion or hot-swap event, the TPS2306 actively limits the inrush current

to the plug-in module. An on-chip linear current amplifier (LCA) provides closed-loop control of the current

sourced to the load circuitry on the module. Subsequently, during normal steady-state loading conditions and

in conjunction with an internal high-voltage charge pump, the LCA provides direct gate drive to fully enhance

the external NMOS pass devices. In addition, the < 4-mV input offset voltage of the LCA allows for the use of

low-value sense resistors. Together, these features minimize the insertion loss across the hot-swap interface.

Control inputs allow the designer to program the maximum current level and the inrush current profile (slew rate)

during start-up. Direct programming of the fault time-out also allows the user to establish how long the HSPM

can operate in the current control mode prior to turning off the pass elements. The high degree of user

programmability allows the TPS2306 to be configured for the specific load and bulk capacitance charging

requirements of the target system.

A second level of power bus protection is provided in the form of fast overcurrent comparators monitoring the

load current levels of the two channels. Should a short-circuit event’s edge rate ever exceed the slew rate of

the LCA, the overcurrent comparator immediately latches off the external NMOS devices, overriding the timeout

period. The overcurrent threshold is also user-programmable.

Supply sequencing control is provided via four comparator inputs to independently control the ramp-up and

ramp-down of each supply output (see Figure 1). The TPS2306 also provides a TTL and CMOS compatible

enable input for external control of the supply outputs, and a low-power sleep mode. Also, the open-drain FAULT

output provides single-line fault reporting to the system host for the two monitored supplies.

Copyright

 2000, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

IMAX1

UP1

ENBL

IREF

CT

GND

UP2

IMAX2

VCC/CS1

DOWN1

GATE1

FAULT

CPUMP

GATE2

DOWN2

CS2

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