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| Power Management ICs Combine Discrete Functions into Single-Chip
Solutions | | | |
CHANDLER, Ariz., - Microchip Technology Inc., introduced the TC1303/TC1304 and
TC1313 series of power management integrated circuits that combine a synchronous buck switching regulator, low
dropout regulator (LDO) and power-good function into single-chip solutions. These five new devices offer low-power
and low-cost advantages for a variety of battery-operated and dual-output-voltage systems.
The five power
management devices being announced today are the:
• TC1303A: A 500 milliAmp synchronous
buck regulator and 300 milliAmp LDO with a power-good function on the dc-to-dc converter output.
• TC1303B: A 500 milliAmp synchronous buck regulator and 300 milliAmp LDO with a power-good function on the LDO
output.
• TC1303C: A 500 milliAmp synchronous buck regulator and 300 milliAmp LDO with a
power-good function on the LDO and dc-to-dc converter outputs.
• TC1304: A 500 milliAmp
synchronous buck regulator and 300 milliAmp LDO with power sequencing.
• TC1313: A 500
milliAmp synchronous buck regulator and 300 milliAmp LDO.
These new devices provide a very
cost-effective solution with minimal board space because of the high-frequency operation of the buck converter,
which reduces the size requirements of the external inductor and capacitor; the minimal external component
requirement by the LDO and the small DFN (dual flat no leads) package size.
The switching
regulator is a synchronous buck dc-dc converter with a PWM oscillator operating at a fixed 2.0 MHz when the load is
heavy. It offers a low-current operating mode, or pulse frequency operation (PFM), when the load is light in
stand-by mode. The dc-dc regulator has adjustable and fixed-output voltage options, allowing the user to dial in the
exact voltage needed or to use a fixed option to minimize the external part count.
The
auxiliary linear LDO regulator can operate at loads of up to 300 milliAmps and has a typical dropout voltage of 137
milliVolts at a 200 milliAmp load. This allows the LDO to operate with minimum differential voltage. The LDO is
stable with a single 1.0 microfarad ceramic capacitor on the output.
The devices are
externally compensated and offer a number of protection features, including undervoltage lockout (UVLO),
overtemperature protection and output short circuit protection. The TC1303/TC1313 devices offer individual shutdown
controls for the two regulators, and an operating junction temperature range of -40 degrees Celsius to +125 degrees
Celsius. The small thermally enhanced package (10-lead, 3x3mm DFN) minimizes board space and allows for excess heat
to be extracted from the package.
In the case of the TC1304, the power-good circuit in
conjunction with the SHDN pin provides a power-sequencing function that requires the LDO output to be operating
within specification before the switcher is allowed to activate. Conversely, the sequencing circuit turns off the
switcher output prior to the LDO output when the device is shutting down.
The TC1303/TC1304
and TC1313 series provide an ideal solution for applications like: computing (FPGA power source) and hand-held,
battery-powered products (cell phones and MP3 players). For computers, the TC1303 family provides an excellent
solution for supplying dual output voltages for core voltage and I/O requirements. In addition, the power-good
function can be used to signal when the power is within specific limits. Or, the TC1304 can be used to sequence
power so that voltage is applied to one circuit before the other is powered up.
For
hand-held battery-powered applications, the TC1303/TC1304 and TC1313 series provide an ideal fit because they have
low quiescent current, power savings PFM mode and high conversion efficiency along with an auxiliary LDO for various
applications. The major application is to supply low voltage core voltages and higher voltages for the I/O from a
Lithium-Ion battery source.
To help engineers get started and to demonstrate the
effectiveness of these power management solutions, Microchip is offering the TC1303BDM-DDBK1 Demonstration Board for
$30 US beginning in August 2005. |
Miércoles, 20 Julio, 2005 - 11:00 |
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