MAXIM MAX1846 free download

File name MAX1846-MAX1847.pdf

19-2091; Rev 0; 8/01 High-Efficiency, Current-Mode, Inverting PWM Controller General Description MAX1846/MAX1847 high-efficiency PWM inverting controllers allow designers to implement compact, lownoise, negative-output DC-DC converters for telecom and networking applications. Both devices operate from +3V to +16.5V input and generate -2V to -200V output. To minimize switching noise, both devices feature a current-mode, constant-frequency PWM control scheme. The operating frequency can be set from 100kHz to 500kHz through a resistor. The MAX1846 is available in an ultra-compact 10-pin µMAX package. Operation at high frequency, compatibility with ceramic capacitors, and inverting topology without transformers allow for a compact design. Compatibility with electrolytic capacitors and flexibility to operate down to 100kHz allow users to minimize the cost of external components. The high-current output drivers are designed to drive a P-channel MOSFET and allow the converter to deliver up to 30W. The MAX1847 features clock synchronization and shutdown functions. The MAX1847 can also be configured to operate as an inverting flyback controller with an Nchannel MOSFET and a transformer to deliver up to 70W. The MAX1847 is available in a 16-pin QSOP package. Current-mode control simplifies compensation and provides good transient response. Accurate current-mode control and over current protection are achieved through low-side current sensing. o 90% Efficiency o +3.0V to +16.5V Input Range o -2V to -200V Output o Drives High-Side P-Channel MOSFET o 100kHz to 500kHz Switching Frequency o Current-Mode, PWM Control o Internal Soft-Start o Electrolytic or Ceramic Output Capacitor o The MAX1847 also offers: Synchronization to External Clock Shutdown N-Channel Inverting Flyback Option Features MAX1846/MAX1847 Ordering Information PART MAX1846EUB MAX1847EEE TEMP. RANGE -40°C to +85°C -40°C to +85°C PIN-PACKAGE 10 µMAX 16 QSOP Typical Operating Circuit POSITIVE VIN Applications Cellular Base Stations Networking Equipment Optical Networking Equipment SLIC Supplies CO DSL Line Driver Supplies Industrial Power Supplies Automotive Electronic Power Supplies Servers FREQ PGND VL IN EXT P NEGATIVE VOUT MAX1846 MAX1847 COMP CS REF GND FB Pin Configurations appear at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. High-Efficiency, Current-Mode, Inverting PWM Controller MAX1846/MAX1847 ABSOLUTE MAXIMUM RATINGS IN, SHDN to GND ...-0.3V to +20V PGND to GND ...-0.3V to +0.3V VL to PGND for VIN 5.7V...-0.3V to (VIN + 0.3V) VL to PGND for VIN > 5.7V ...-0.3V to +6V EXT to PGND ...