View MIC4827YMM_5123535.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

mic4827 low input voltage, 180v pp output voltage, el driver general description micrel?s mic4827 is a high output voltage, dc to ac con- verter, designed for driving el (electroluminescent) lamps. the device operates from an input voltage range of 1.8v to 5.5v, making it suitable for 1-cell li-ion and 2- or 3- cellalkaline/nicad/nimh battery applications. the mic4827 converts a low voltage dc input to a 180v pp ac output signal that drives the el lamp. the mic4827 is comprised of two stages: a boost stage, and an h-bridge, lamp driver, stage. the boost stage steps the input voltage up to +90v. the h-bridge stage then alternately switches the +90v output to each terminal of the el lamp, thus creating a 180v pp ac signal to drive the el lamp and generate light. the mic4827 features separate oscillators for the boost- and h-bridge stages. external resistors independently set the operating frequency of each stage. this flexibility allows the el lamp circuit to be optimized for maximum efficiency and brightness. the mic4827 uses a single inductor and a minimum number of external components, making it ideal for portable, space-sensitive applications. the mic4827 is available in an 8-pin msop package with an ambient temperature range of ?40c to +85c. features ? 1.8v to 5.5v dc input voltage ? 180v pp regulated ac output waveform ? independently adjustable el lamp frequency ? independently adjustable boo st converter frequency ? 0.1a shutdown current applications ? lcd panel backlight ? cellular phones ? pdas ? pager ? calculators ? remote controls ? portable phones typical application micrel inc. ? 2180 fortune drive ? san jose, ca 95131 ? usa ? tel +1 ( 408 ) 944-0800 ? fax + 1 (408) 474-1000 ? http://www.micrel.com july 2009 m9999-070709-a (408) 955-1690 332k 3.32m c out 0.033f/100v d1 bav20ws l1 220h 2in 2 el lamp 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 c in 10f v in time (2ms/div) v b (50v/div) v a (50v/div) v a ? v b (50v/div) high voltage el driver
micrel, inc. mic4827 july 2009 2 m9999-070709-a (408) 955-1690 ordering information part number standard pb-free ambient temp. range package mic4827bmm MIC4827YMM ?40 to +85c 8-pin msop pin configuration 8-pin msop (mm) pin description pin number pin name pin function 1 vdd supply (input): 1.8v to 5.5v. 2 rsw switcher resistor (external component): set switch frequency of the internal power mosfet by connecting an external resistor to vdd. connecting the external resistor to gnd disables th e switch oscillator and shuts down the device. 3 rel el resistor (external component): se t el frequency of the internal h-bridge driver by connecting an external resistor to vdd. connecting the external resistor to gnd disables the el oscillator. 4 gnd ground return. 5 sw switch node (input): internal high-voltage power mosfet drain. 6 cs regulated boost output (external component): connect the output capacitor of the boost regulator and connect to the cathode of the diode. 7 vb el output: connect to one end of t he el lamp. polarity is not important. 8 va el output: connect to the other end of the el lamp. polarity is not important.
micrel, inc. mic4827 july 2009 3 m9999-070709-a (408) 955-1690 absolute maximum ratings (1) supply voltage (v dd )............................................?0.5 to 6v output voltage (v cs ) ........................................?0.5 to 100v freq. control voltage (v rsw , v rel )....... ?0.5 to (v dd + 0.3v) power dissipation @ t a = 85c ..............................200mw storage temperature (t s ) .........................?65c to +150c eds rating (3) operating ratings (2) supply voltage (v dd ).................................... +1.8v to +5.5v lamp drive frequency (f el ) ....................... 60hz to 1000hz switching transistor frequency (f sw ) ........8khz to 200khz ambient temperature (t a ) .......................... ?40c to +85c junction thermal resistance pdip ( ja ) ........................................................206c/w electrical characteristics (4) v in = v dd = 3.0v; r sw = 560k ?; r el = 1.0m ?; t a = 25c, bold values indicate ?40c< t a < +85c, unless noted. symbol parameter condition min typ max units r ds(on) on-resistance of switching transistor i sw = 100ma, v cs = 85v 3.8 7.0 ? 85 90 95 v v cs output voltage regulation v dd = 1.8v to 5.5v 83 97 v 170 180 190 v v a ? v b output peak-to-peak voltage v dd = 1.8v to 5.5v 166 194 v v en-l input low voltage (turn-off) v dd = 1.8v to 5.5v 0.5 v v en-h input high voltage (turn-on) v dd = 1.8v to 5.5v v dd ? 0.5 v i sd shutdown current, note 5 r sw = low; r el = low; v dd = 5.5v 0.01 0.1 0.5 a a i vdd input supply current r sw = high; r el = high; v cs = 85v; v a , v b open 21 75 a i cs boosted supply current r sw = high; r el = high; v cs = 85v; v a , v b open 200 400 a i in input current including inductor current v in = v dd = 1.8v (see test circuit) 28 ma f el v a ? v b output drive frequency 285 360 435 hz f sw switching transistor frequency 53 66 79 khz d switching transistor duty cycle 90 % notes: 1. exceeding the absolute maximum rating may damage the device. 2. the device is not guaranteed to function outside its operating rating. 3. devices are esd sensitive. handling precautions recommended. 4. specification for packaged product only. 5. shutdown current is defined as the sum of current going into pin 1, 5, and 6 when the device is disabled.
micrel, inc. mic4827 july 2009 4 m9999-070709-a (408) 955-1690 test circuit c out 0.033f/100v d1 bav20ws l1 220h 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 c in 10f 10nf v in 562k 3.32m
micrel, inc. mic4827 july 2009 5 m9999-070709-a (408) 955-1690 typical characteristics 0 1 2 3 4 5 6 7 1 2 345 6 (ecnatsiserhctiws ) input voltage (v) switch resistance vs. input voltage 10 100 1000 10000 0.1 1 1 0 )zh(ycneuqerfle el resistor (m ) el frequency vs. el resistor 1 10 100 1000 100 1000 10000 )zhk(ycneuqerfgnihctiws switch resistor (k ) switching frequency vs. switch resistor 0 20 40 60 80 100 120 -40-200 2040608010 0 )zhk(ycneuqerf temperature ( c) switching frequency vs. temperature r sw = 332k v in = 3.0v r sw = 442k r sw = 562k 0 20 40 60 80 100 120 12345 6 )zh(ycneuqerfgnihctiws input voltage (v) switching frequency vs. input voltage r sw = 562k r sw = 442k r sw = 332k 0 50 100 150 200 250 300 350 400 12345 6 )zh(ycneuqerfle input voltage (v) el frequency vs. input voltage r el = 1m r el = 2m r el = 3.32m
micrel, inc. mic4827 july 2009 6 m9999-070709-a (408) 955-1690
micrel, inc. mic4827 july 2009 7 m9999-070709-a (408) 955-1690 block diagram q 1 q 2 /q 3 /q 4 el oscillator gnd v ref 4 vb el lamp 7 va 8 cs 6 sw c out d1 l1 220h 5 v dd 1 rsw r sw c in 2 rel r el 3 switch oscillator v in figure 1. mic4827 block diagram functional description overview the mic4827 is a high-voltage el driver with an ac output voltage of 180v peak-t o-peak capable of driving el lamps up to 6in 2 . input supply current for the mic4827 is typically 21a with a typical shutdown current of 10na. the high voltage el driver has two internal oscillators to control the switching mosfet and the h-bridge driver. both of the internal oscillators? frequencies can be individually programmed through the external resistors to maximi ze the efficiency and the brightness of the lamps. regulation referring to figure 1, initially power is applied to v dd . the internal feedback voltage is less than the reference voltage causing the internal comparator to go low which enables the switching mosfet?s oscillator. when the switching mosfet turns on, current flows through the inductor and into the switch . the switching mosfet will typically turn on for 90% of the switching frequency. during the on-time, energy is stored in the inductor. when the switching mosfet turns off, current flowing into the inductor forces the voltage across the inductor to reverse polarity. the voltage across the inductor rises until the external diode conducts and clamps the voltage at v out + v d1 . the energy in the inductor is then discharged into the c out capacitor. the internal comparator continues to turn the switching mosfet on and off until the internal feedback voltage is above the reference voltage. once the internal feedback voltage is above the reference voltage, the internal comparator turns off the switching mosfet?s oscillator. when the el oscillator is enabled, v a and v b switch in opposite states to achieve a 180v peak-to-peak ac output signal. the external resistor that connects to the rel pin determines the el frequency.
micrel, inc. mic4827 july 2009 8 m9999-070709-a (408) 955-1690 time (2ms/div) v b (50v/div) v a (50v/div) v a ? v b (50v/div) v in = 3.0v l = 220h c out = 0.033 f lamp = 2in 2 r sw = 332k r el = 3.32m figure 2. 108hz typical output waveform switching frequency the switching frequency of the converter is controlled via an external resistor between r sw pin and v dd pin of the device. the switching frequency increases as the resistor value decreases. for resistor value selections, see the ?typical characteri stics: switching frequency vs. switch resistor? or use the equation below. the switching frequency range is 8khz to 200khz, with an accuracy of 20%. () = mr 36 (khz)f sw sw el frequency the el lamp frequency is controlled via an external resistor connected between r el pin and v dd pin of the device. the lamp frequency in creases the resistor value decreases. for resistor value selections, see the ?typical characteristics: el frequency vs. el resistor? or use the equation below. the switching frequency range is 60hz to 1000hz, with an accuracy of 20%. () () mr 360 hzf el el time (2ms/div) v b (50v/div) v a (50v/div) v a ?v b (50v/div) v in = 3.0v l = 220h c out = 0.033 f lamp = 2in 2 r sw = 562k r el = 1m figure 3. 180hz output waveform in general, as the el lamp frequency increases, the amount of current drawn from the battery will increase. the color of the el lamp and the intensity are dependent upon its frequency. time (2ms/div) v b (50v/div) v a (50v/div) v a ?v b (50v/div) figure 4. 360hz output waveform enable function the enable function of the mic4827 is implemented by switching the r sw and r el resistor between ground and v dd . when r sw and r el are connected to ground, the switch and the el oscillators are disabled; therefore the el driver becomes disabled. when these resistors connect to v dd , both the oscillators will function and the el driver is enabled.
micrel, inc. mic4827 july 2009 9 m9999-070709-a (408) 955-1690 application information inductor in general, smaller value inductors, which can handle more current, are more suitable to drive larger size lamps. as the inductor value decreases, the switching frequency (controlled by r sw ) should be increased to avoid saturation or the input voltage should be increased. typically, inductor values ranging from 220h to 560h can be used. murata offers the lqh3c series up to 560h and lqh4c series up to 470h, with low dc resistance. a 220h murata (lqh4c221k04) inductor is recommended for driving a lamp size of 3 square inches. it has a maximum dc resistance of 4.0 ? diode the diode must have a high reverse voltage (150v), since the output voltage at the cs pin can reach up to 110v. a fast switching diode with lower forward voltage and higher reverse voltage (150v), such as bav20ws, can be used to enhance efficiency. output capacitor low esr capacitors should be used at the regulated boost output (cs pin) of the mic4827 to minimize the switching output ripple voltage. selection of the capacitor value will depend upon the peak inductor current, inductor size, and the load. murata offers the grm42-6 series with up to 0.047f at 100v, with a x7r temperature coefficient in 1206 surface-mount package. typically, values ranging from 0.01f to 0.1f at 100v can be used for the regulated boost output capacitor pre-designed application circuit r1 332k r2 3.32m li-ion battery v in 3.0v to 4.2v c1 0.22 f/10v murata grm39x7r 224k10 c out 0.01 f/100v grm40x7r103k d1 bav20ws l1 220 h murata lqh4c221k04 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 3in 2 lamp c2 10 f/6.3v murata grm42-6x5r106k6.3 v in i in v a ? v b f el lamp size 3.3v 28ma 180v pp 106hz 3in 2 time (2ms/div) v b (50v/div) v a (50v/div) v a ev b (50v/div) figure 5. typical 100hz el driver for 3in 2 lamp
micrel, inc. mic4827 july 2009 10 m9999-070709-a (408) 955-1690 r1 332k r2 3.32m v in 2.4v to 5.5v c out 0.033f/100v grm42-6x7r333k100 d1 diodes bas20w l1 220h murata lqh4c221k04 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 el lamp lsi x533-13 c2 10f/6.3v murata grm42-6x5r106k6.3 v in i in v a ? v b f el lamp size 3.3v 18ma 180v pp 104hz 2in 2 time (2ms/div) v b (50v/div) v a (50v/div) v a ?v b (50v/div) figure 6. typical el driver for 2in 2 lamp with c s = 0.033 f
micrel, inc. mic4827 july 2009 11 m9999-070709-a (408) 955-1690 r1 562k r2 3.32m v in 3.3v to 5.5v c out 0.033f/100v grm42-2x7r104k100 d1 diodes bas20w l1 560k murata lq32cn561k21 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 el lamp lsi x533-13 c2 10f/6.3v murata grm42-6x5r106k6.3 v in i in v a ? v b f el lamp size 3.3v 21ma 180v pp 102hz 2in 2 time (2ms/div) v b (50v/div) v a (50v/div) v a ?v b (50v/div) figure 7. typical el driver for 2in 2 lamp with 560 h inductor
micrel, inc. mic4827 july 2009 12 m9999-070709-a (408) 955-1690 r1 562k r2 3.32m v in 1.5v c out 0.01f/100v grm42-2x7r104k100 d1 diodes bas20w l1 220h murata lqh4c221k04 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 el lamp c2 10f/6.3v murata grm42-6x5r106k6.3 v dd 1.8v to 5.5v c1 0.01f/50v murata grm42-6x5r106k6.3 v in i in v dd i dd v a ? v b f el lamp size 1.5v 26ma 3.0v 32a 180v pp 104hz 1.6in 2 time (2ms/div) v b (50v/div) v a (50v/div) v a ?v b (50v/div) figure 8. typical split power supplies applications
micrel, inc. mic4827 july 2009 13 m9999-070709-a (408) 955-1690 r1 1m r2 3.32m v in 1.8v to 3.3v (2x alkaline batteries) c out 0.1f/100v grm42-2x7r104k100 d1 diodes bas20w l1 220h murata lq32cn561k21 15 6 8 7 2 3 4 sw cs va vb vdd rsw rel gnd mic4827 el lamp elite 12607-n c2 10f/6.3v murata grm42-6x5r106k6.3 v in i in v a ? v b f el lamp size 3.0v 31ma 180v pp 104hz 5.3in 2 time (2ms/div) v b (50v/div) v a (50v/div) v a ? v b (50v/div) figure 9. typical el driver remote control lamp (blue phosphor) applications
micrel, inc. mic4827 july 2009 14 m9999-070709-a (408) 955-1690 package information 8-pin msop (mm)
micrel, inc. mic4827 july 2009 15 m9999-070709-a (408) 955-1690 micrel, inc. 2180 fortune drive san jose, ca 95131 usa tel +1 (408) 944-0800 fax +1 (408) 474-1000 web http:/www.micrel.com the information furnished by micrel in this data sheet is believed to be accurate and reliable. however, no responsibility is a ssumed by micrel for its use. micrel reserves the right to change circuitry and specifications at any time without notification to the customer. micrel products are not designed or autho rized for use as components in life support appliances, devices or systems where malfu nction of a product reasonably be expected to result in pers onal injury. life support devices or systems are devices or systems that (a) are intended for surgical impla into the body or (b) support or sustain life, and whose failure to perform can be reasonably expect ed to result in a significan t injury to the user. a purchaser?s use or sale of micrel products for use in life support appliances, devices or systems is a purchaser?s own risk and purchaser agrees to fully can nt indemnify micrel for any damages re sulting from such use or sale. ? 2001 micrel, incorporated.

▲Up To Search▲

Price & Availability of MIC4827YMM

	To Download MIC4827YMM Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .