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Maxim > Design Support > Technical Documents > Reference Designs > Power-Supply Circuits > APP 4361
Keywords: SEPIC, print head power supply
REFERENCE DESIGN 4361 INCLUDES: Tested Circuit Schematic BOM Description Test Data
Reference Design Ensures Dynamic Output Voltages
for a Print-Head Power Supply
By: Surya Prakash
Mar 19, 2009
Abstract:
This article
describes some important design parameters for managing power in a printer. The
reference design shows how to use a MAX15005 power-supply controller as a SEPIC circuit to obtain a high-
variable output voltage for a print-head power supply. The circuit schematics, bill of materials (BOM), test
measurements, and results are provided.
Introduction
This reference design is a solution for obtaining a high-variable output voltage for a printer-head power
supply. The design includes the complete circuit schematic, bill of materials (BOM), efficiency measurements,
and test results.
Some Basics of Printer Design
The increasing speed of printers has led to higher power dissipation and higher temperatures in the print
head. If the temperature in the printer becomes sufficiently high, the ink will smudge. When the temperature is
low, the ink becomes illegible. Consequently, thermal management of the print head is critical to ensuring
high-quality printing. A microcontroller is required to adjust the printing speed and thus maintain the operating
temperature between these two limits. The printer's motor speed is adjusted by applying variable DC voltages.
Reference Design Overview
This reference design features the MAX15005 power-supply controller and provides a dynamic DC voltage (up
to 45V) to the printer's motor. The output voltage can be varied by applying a PWM signal from the
microcontroller to the SS pin of MAX15005 through a RC filter. During startup, the printer's motor draws more
current to magnetize its field. The MAX15005A is particularly useful now because it offers hiccup-mode
protection. The MAX15005 can enter hiccup mode and supply power at a reduced rate to protect all circuit
components. Once magnetization is over, the motor draws normal current and the converter operates in
regulation mode.
Specifications and Design Setup
The reference design meets the following specifications:
Input voltage: 32V to 45V
Output voltage: 25V to 45V (varied externally from the microcontroller)
Output current: 0 to 2A
Output ripple: ±0.5V
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Verzeichnis
- ・ Blockdiagramm on Seite 1 Seite 2
- ・ Technische Daten on Seite 1
