bus ic Introduction dc/dc converter motor driver ic E 910.22 Wide range flyb. SMPS with WD ÿE 910.24 | 25 | 26 PFM controller family ripple counter driver ic I/O ic Sensor interface ic sensor ic ip’s E 910.27 Step down converter, fully integr. E 981.03 Energy storage controller E 910.28 Step down converter, for ext. FET ÿ Adjustable, wide input range PFM controller family E910.24 | 25 | 26 features description ÿ Supply voltage range of 3V to 60V The family of highly flexible, easy to use PFM controllers is ideal ÿ Up to 90% efficiency for the use in wide input range switching regulator applications. ÿ 40µA standby current ÿ 180µA circuit operating current An advanced PFM control scheme gives these devices the benefits ÿ 1.5V to 24V or higher adjustable output voltage of PWM converters with high efficiency for heavy loads, while us- ÿ Up to 300kHz switching frequency ing very low operating current for light loads to maintain excel- ÿ Improved current-limited PFM control scheme lent behaviour with output load variation. ÿ High current driver for external MOSFET ÿ Under-voltage lockout and thermal shutdown The switching circuits are suitable for topologies requiring low ÿ – 40°C to + 125°C operating temperature side FET, such as boost, flyback, Sepic, etc. Depending on the uti- ÿ E910.26 basis version lized topology the controllers are capable of producing regulated ÿ E910.24 additive with peak current halving for positive or negative output voltage. pinning medium loads and extended max. switch-on-time ÿ E910.25 additive with peak current halving for 1 Name PGND 2 AGND 3 ISEN 4 VFB 5 ON 6 VS 7 VSM 8 MDRV Operating from 3V to 60V supply and in temperature ranges from medium loads and extended max. switch-on-time – 40°C to + 125°C the device is well suited for automotive appli- and fault protection cations. Requiring a minimum number of external components, Pin package ÿ SO8n package these regulators are simple to use and cost-saving. application Self-protection features include an overload detection circuit, an ÿ Minimum component DC/DC converters overtemperature shutdown under fault conditions and an under- ÿ 14V, 28V or 42V automotive systems voltage lockout. ÿ Power conditioning for portable equipment ÿ High efficiency on-card switching regulators Block diagram VBAT Description Driver power ground pin. Connect pin to the current sense resistor, the (-) terminal of the input capacitor and the (-) terminal of the output capacitor. Due to high currents, and high frequency operation of the IC, a low impedance circuit ground plane is highly recommended. Analog ground pin. This pin provides a clean ground for the controller circuitry: The output voltage sensing resistors should be connected to this ground pin. This pin is connected to the IC substrate. Connect to the (-) terminal of the output capacitor. Current sense input pin. Voltage generated across an external sense resistor is fed into this pin. Filters extensive high-frequency noise. Positive feedback pin. Connect to SMPS output via external resistor divider to set output voltage and is referenced to 1.22V. For best stability, keep VFB lead as short as possible and VFB stray capacitance as small as possible. Switch ON input. Tie this pin to ground to force the IC into idle mode. A voltage of VSM or higher switches the controller in operating mode. Main supply input. Filter out high-frequency noise with a 100nF ceramic capacitor placed close to the pin to PGND. Internal 5V regulator output. The driver and all control circuits are powered from this voltage. Decouple this pin to PGND with a minimum of 4.7µF tantalum and parallel 100nF ceramic capacitors. Drive output. Drives the gate of the external MOSFET between PGND and VSM. Connect the external MOSFET via a damping resistor to this pin. PGND 1 8 AGND 2 7 ISEN 3 6 VFB 4 5 MDRV VSM VS ON so8 VS VSM int. Supply & References ON On/Off Logic Gain Control (1) VSM VOut MDRV DRV PFM Circuit Instr. Ampl. + - Overload Protection (2) AGND VFB E910.24│25│26 PGND 30 ISEN Note ELMOS Semiconductor AG (below ELMOS) reserves the right to make changes to the product contained in this publication without notice. ELMOS assumes no responsibility for the use of any circuits described herein, conveys no licence under any patent or other right, and makes no representation that the circuits are free of patent infringement. While the information in this publication has been checked, no responsibility, however, is assumed for inaccuracies. ELMOS does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of a life-support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications. Copyright © 2007 ELMOS Reproduction, in part or whole, without the prior written consent of ELMOS, is prohibited. www.elmos.de | [email protected] elmos product catalog 2007/2008 31