ETC AT1604

AT1604
5-Bit Synchronous-Rectifier PWM Controller
Features
General Description
˙Drives two N-channel MOSFETs
˙Operates from +5V and +12V input
˙Simple single-loop control
-Voltage-mode PWM control
˙Fast transient response
- High-bandwidth error amplifier
- Full 0% to 100% duty ratio
˙Excellent output voltage regulation
- ± 1% over line voltage and temperature
˙TTL-compatible 5 bit digital-to-analog output
voltage selection
- Wide range 1.3VDc to 3.5VDC
- 0.1V binary steps from 2.1VDC to 3.5VDC
- 0.05V binary steps from 1.3VDC to 2.05VDC
˙Power-good output voltage monitor
˙Over-voltage and over-current fault monitors
-Does not require extra current sensing element
˙Small converter size
-Constant frequency operation
-200 kHz free-running oscillator programmable
from 50 kHz to over 1 MHz
The AT1604 provides complete control and
protection for a DC-DC converter optimized for
high-performance microprocessor applications. It is
designed to drive two N-channel MOSFETs in a
synchronous-rectified buck topology. The AT1604
integrates all of the control, output adjustment,
monitoring and protection functions into a single
package.
Applications
˙Power supply for PentiumTM, PentiumTM Pro,
PowerPCTM and AlphaTM Microprocessors
˙High-power 5V to 3.xV DC-DC regulators
˙Low-voltage distributed power supplies
The AT1604 includes a fully-TTL compatible 5-bit
digital-to-analog converter (DAC) that adjusts the
output voltage from 2.1VDC to 3.5VDC in 0.1V
increments and from 1.3VDC to 2.1VDC in 0.05V
steps. The precision reference and voltage–mode
regulator hold the selected output voltage to within
± 1% over temperature and line voltage variations.
The AT1604 provides simple, single feedback loop,
voltage-mode control with fast transient response. It
includes a 200kHz free-running triangle-wave
oscillator that is adjustable from below 50kHz to
over 1MHz. The error amplifier features a 12MHz
gain-bandwidth product and 6V/μs slew rate which
enable high converter bandwidth for fast transient
performance. The resulting PWM duty ratio ranges
from 0% to 100%.
The AT1604 monitors the output voltage with a
window comparator that tracks the DAC output and
issues a Power Good signal when the output is
within ± 10% of the targeted value. The AT1604
protects against over-current conditions by
inhibiting PWM operation. Built-in over-voltage
protection triggers an external SCR to crowbar the
input supply. The AT1604 monitors the current by
using the rDS(on) of the upper MOSFET, which
eliminates the need for a current sensing resistor.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
Preview the document, detail datasheet contact to our service department.
AT1604
5-Bit Synchronous-Rectifier PWM Controller
Block Diagram
Pin Configuration
AT1604 (20-Pin SOIC)
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
Preview the document, detail datasheet contact to our service department.