Power driver for CD-ROM/DVD

Transcription

1 Power driver for CD-ROM/DD BHF BHF BHF is an IC which includes a ch PWM driver for motor drive of CD-ROM and DD-ROM players, and a pressure circuit for power MOSFET gate drive in output stage. Power MOS FET is adopted in an output stage to reduce power consumption in the set. Applications CD-ROM, DD-ROM and other related optical discs External dimensions (Unit : mm).. Features ) One channel of power MOS-H bridges are contained. ) Built-in charge pump circuit for G (DD ). ) Low power consumption. ) Low ON-resistance. ) A miniature package of SSOP-B is used. ) Available for analog input. ) Direct PWM drive system. ) Dead zone is small. ) Excellent gain accuracy is obtained through a voltage feedback circuit. ) An external component is little min. SSOP-B... Absolute maximum ratings (Ta= C) Parameter Symbol Limits Unit Control circuit power supply voltage Pre-driver power supply voltage Driver output current Power dissipation Operating temperature range Storage temperature range CC G(pin) ) On less than %(percentage occupied by copper foil), mm mm, t=.mm, glass epoxy mounting. Reduce power by.mw for each degree above Ta= C. IO Pd Topr Tstg to to mw C C Recommended Operating Conditions (Ta= C) Parameter Symbol Min. Typ. Max. Unit Control circuit power supply voltage CC / DD... /

2 BHF Block diagram M R F M NF C NF AMP H BRIDGE k k k G PRE DRIER LOGIC CHARGE PUMP TSD SAW OSC CC / DD Descriptions of terminal Pin No. G Descriptions Power supply for Gate of power MOS Tr. Pin No. C Descriptions Center voltage input CP Capacitor connect pin for charge pump() NF Feedback filter terminal CM Capacitor connect pin for charge pump() M Power supply for power MOS Tr. CC / DD Power supply for pre block and charge pump OUTR Inverted output Gnd for pre block and charge pump P Gnd for power MOS Tr. Triangular wave output OUTF Non-inverted output OPOUT Op-amp output M Power supply for power MOS Tr. OPIN Op-amp input Input for stand-by control Note: Non-inverted output and inverted output of driver are the polarity to an input terminal, when the pre op-amplifier is used at the inverting amplifier. /

3 BHF Electrical characteristics (Unless specified particularly Ta= C, CC /dd=, C =., RL=ΩµH) (Circuit current) Parameter Symbol Min. Typ. Max. Unit Conditions Stand-by on current Current consumption upon no signal Current consumption upon operation (PWM driver) Output on-resistance Output offset voltage oltage gain Gain error by polarity Input dead zone (Pre Op-amplifier) Offset voltage High level output voltage Low level output voltage Output sink current Output source current (Triangle wave generation circuit) Output source current Output sink current Oscillation frequency (Charge pump circuit) Output voltage Oscillation frequency (Stand-by terminal voltage drop stand-by ON-level input voltage OFF-level input voltage (G terminal voltage drop mute) Mute ON-level input voltage Mute OFF-level input voltage (C terminal voltage drop mute) Mute ON-level input voltage Mute OFF-level input voltage This product is not designed for protection against radioactive rays. When stand-by terminal voltage is below.(typ.), driver unit and triangular wave generating circuit are muted, allowing stand-by mode. When G terminal voltage is below. times CC/DD, only driver unit is muted. When C terminal voltage is below.(typ.), only driver unit is muted. IST IQ IQ RON OO GC GC DB OFOP OOH OOL I SIOP I SOOP ISO ISI f G fcp STON STOF GMON GMOF CMON CMOF Ω m db db m m µa µa khz khz Sum of ON-resistance of top and that of bottom =pf CC / DD= CC / DD= /

4 BHF Optical disc ICs / Equivalent circuit diagram Pin. No Equivalent circuit diagram Equivalent circuit diagram G CP CC CM CC CC CC OPOUT CC OPIN Pin. No CC C k k CC NF C M OUTF P C P OUTR M CC k p k k k k k p k k p k k

5 BHF Description of operation. PWM driver H bridge driver uses pieces of N-channel MOS Tr on output stage. Polarity of output and PWM duty are changed in proportion to differential voltage and absolute value of input sandwiching ref. Load is direct-pwm driven by square wave of this changing duty. This driver is voltage feedback type, and gain is constant independent of power voltage fluctuation.. Triangular wave generating circuit ) Free-running oscillation frequency of triangular wave can be set by external capacitor Ct (between pin. and ). Amplitude of triangular wave is approx.. for H-level, and approx.. for L-level. Ratio of source current against sink current from terminal is :. Therefore, oscillation frequency can be shown by the formula below. ft =.µ Ct(..) [Hz] about. about. t t t Triangular wave generating circuit and triangular waveform /

6 BHF Application L : Battery center M R F M NF C NF AMP H BRIDGE k k k G PRE DRIER LOGIC CHARGE PUMP TSD SAW OSC CC / DD to BHAF G Signal Note on use. G voltage is double of pin. voltage. Therefore, if without supply on pin, charge pump do not generate G. And adjust CC, not to over absolute maximum rating of G.. In case of supply G by external power supply, please remove capacitor between pin and pin.. When the temperature of chip reaches (typ.), output current is cut off, and it is recovered when the temperature reaches (typ.) again.. Connect a by-pass capacitor between CC-pin and -pin of this IC as possible as near. Electrical characteristic curves OUTPUT OLTAGE : O() CC / DD / M= C=. RL( ) ΩµH ΩµH ΩµH ΩµH..... INPUT OLTAGE : IN() ΩµH OUTPUT OLTAGE : O() CC / DD / M= C=. RL=ΩµH INPUT OLTAGE : IN(m) G() CC=..... IGL() CC= CC= Fig. Input/output characteristics Fig. I/O characteristics at minute input Fig. Charge pump load current output voltage /

7 Appendix Notes No technical content pages of this document may be reproduced in any form or transmitted by any means without prior permission of ROHM CO.,LTD. The contents described herein are subject to change without notice. The specifications for the product described in this document are for reference only. Upon actual use, therefore, please request that specifications to be separately delivered. Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set. Any data, including, but not limited to application circuit diagrams information, described herein are intended only as illustrations of such devices and not as the specifications for such devices. ROHM CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any third party's intellectual property rights or other proprietary rights, and further, assumes no liability of whatsoever nature in the event of any such infringement, or arising from or connected with or related to the use of such devices. Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or otherwise dispose of the same, no express or implied right or license to practice or commercially exploit any intellectual property rights or other proprietary rights owned or controlled by ROHM CO., LTD. is granted to any such buyer. Products listed in this document are no antiradiation design. The products listed in this document are designed to be used with ordinary electronic equipment or devices (such as audio visual equipment, office-automation equipment, communications devices, electrical appliances and electronic toys). Should you intend to use these products with equipment or devices which require an extremely high level of reliability and the malfunction of with would directly endanger human life (such as medical instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers and other safety devices), please be sure to consult with our sales representative in advance. About Export Control Order in Japan Products described herein are the objects of controlled goods in Annex (Item ) of Export Trade Control Order in Japan. In case of export from Japan, please confirm if it applies to "objective" criteria or an "informed" (by MITI clause) on the basis of "catch all controls for Non-Proliferation of Weapons of Mass Destruction. Appendix-Rev.