Features: ·Provide Tracking of Two External Power Supplies During Power-Up and Power-Down
·Compatible with a Wide Range of External Power Supplies Independent of Output Power
·Bus Voltage Undervoltage Lockout Enables/ Disables CORE and I/O Supplies Together
·Detect Short Circuit on VCORE and VI/O, Disable CORE and I/O Supplies in Either Case
·Output Undervoltage Monitoring
·POK Status (MAX5040)
·Operating VCC Supply Voltage Range: 2.5V to 5.5V
·I/O Voltage Range: VCORE to 4V
·CORE Voltage Range: 0.8V to VI/OApplication·PowerPC Systems
·Embedded DSPs and ASICs
·Embedded 16- and 32-Bit Controller Systems
·Telecom/Base Station/NetworkingSpecifications(All Voltages Referenced to GND)
VCC, NDRV, SDO, and POK ...................................-0.3V to +14V
CORE_FB, UVLO, I/O_SENSE, I/O, CORE ...........-0.3V to +4.25V
All Pins to VCC (except POK).............................................+0.3V
NDRV Continuous Current ................................................50mA
Continuous Current, All Other Pins ...................................20mA
Continuous Power Dissipation (TA = +70)
8-Pin MAX (derate 4.5mW/ above +70) .............,,,,362mW
10-Pin MAX (derate 5.6mW/ above +70) ...........,,,,444mW
Operating Temperature Range ...........................-40 to +85
Junction Temperature......................................................+150
Storage Temperature Range .............................-65 to +150
Lead Temperature (soldering, 10s) .................................+300
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
DescriptionThe MAX5039/MAX5040 provide intelligent control to power systems where two supply voltages need tracking.
These cases include PowerPC®, DSP, and ASIC systems, which require a lower CORE voltage supply and a higher I/O voltage supply.
The MAX5039/MAX5040 control the output voltage of the CORE and I/O supplies during power-up, powerdown, and brownout situations. They ensure that the two power supplies rise or fall at the same rate, limiting the voltage difference between the CORE and I/O supplies.
This eliminates stresses on the processor. The MAX5039/MAX5040 shut down both the CORE and I/O supplies if either one is shorted or otherwise fails to come up.
The MAX5040 provides a power-OK (POK) signal that signals the processor if the CORE supply, the I/O supply, and the system bus supply (VCC) are above their respective specified levels. The MAX5039/MAX5040 are targeted for nominal bus VCC voltages from 4V to 5.5V. The MAX5039/MAX5040 work with CORE voltages ranging from 800mV to about 3V (depending on the gate-to-source turn-on threshold of the external Nchannel MOSFET) and I/O voltages ranging from VCORE to 4V. The MAX5039/MAX5040 provide tracking control of the I/O and CORE voltages using a single external N-channel MOSFET connected across them.
This MOSFET is not in series with the power paths and does not dissipate any additional power during normal system operation. The external MOSFET is only on for brief periods during power-up/power-down cycling so a low-cost, small-size MOSFET with a rating of 1/4th to 1/8th of the normal supply current is suitable.
The MAX5039/MAX5040 are offered in space-saving 8-pin MAX and 10-pin MAX packages, respectively.
MAX5040 Data Sheet
