unisonic technologies co., ltd ulvh431 preliminary linear integrated circuit www.unisonic.com.tw 1 of 6 copyright ? 2016 unisonic technologies co., ltd qw-r103-115.b low-voltage adjustable precision shunt regulator ? description the utc ulvh431 is a low-voltage 3-terminal programmable shunt regulator with guaranteed t hermal stability over full applicable industrial and commercial temperature ranges. the output voltage of utc ulvh431 can be set to any value between v ref (1.24v) and the corresponding maximum cathode voltage (18v) with two external re sistors. the device operates from a lower voltage (1.24v) than the widely used tl431 and tl1431 shunt-regulator references. the utc ulvh431 is an ideal voltage reference in isolated feedback circuits for 3-v to 3.3-v switching-mode power supplies when it is used with an opto-coupler. it has a typical output impedance of 0.25 ? . active output circuitry supplies a very sharp turn-on characteristic, which makes the utc ulvh431 very good substitute for low-voltage zener diode in many applications such as adjustable power supplies and on-board regulation. ? features * adjustable output voltage, v o =v ref to 18 v * low-voltage operation: v ref = 1.24 v * wide operating cathode current range: 100a to 50ma * reference voltage tolerances at 25c * 0.25- ? typical output impedance * -40c ~ 125c specifications ? ordering information pin assignment ordering number package 1 2 3 packing ULVH431G-AE2-R sot-23-3 k r a tape reel ulvh431g-ae3-r sot-23 k r a tape reel
ulvh431 preliminary linear integrated circuit unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r103-115.b ? marking h431 ? pin configuration ? pin description pin no. pin name description 1 cathode cathode voltage 2 ref reference voltage 3 anode anode voltage ? block diagram cathode ref anode + - v ref =1.24v
ulvh431 preliminary linear integrated circuit unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r103-115.b ? absolute maximum rating parameter symbol ratings unit cathode voltage (note 1) v ka 20 v cathode current range i k -25 ~ 50 ma reference current range i ref -0.05 ~ 3 ma operating virtual j unction temperature t j 150 c storage temperature range t stg -65 ~ +150 c note: absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? thermal resistance s characteristics parameter symbol ratings unit package thermal impedance (note 2) ja 206 c/w note: voltage values are with respect to the anode terminal, unless otherwise noted. ? recommended operating conditions parameter symbol min typ max unit cathode voltage v ka v ref 18 v cathode current (continuous) i k 0.1 50 ma operating free-air temperature range t a -40 125 c
ulvh431 preliminary linear integrated circuit unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r103-115.b ? electrical characteristics (t a =25c free-air temperature, unless otherwise specified) parameter symbol test conditions min typ max unit ulvh431-a 1.234 1.24 1.246 v ulvh431-1 1.228 1.24 1.252 v ulvh431-2 1.252 1.265 v reference voltage v ref v ka =v ref , i k =10ma t a =25c ulvh431-3 1.215 1.228 v v ref deviation over full temperature range (note 2) v ref(dev) v ka =v ref , i k =10ma (note 1 and figure 1) 11 31 mv ratio of v ref change to cathode voltage change ka ref v ? v ? i k =10ma (see figure 2), v ka =v ref ~18v -1.5 -2.7 mv/v reference terminal current i ref i k =10ma, r1=10k ? , r2=open (see figure 2) 0.1 0.5 a i ref deviation over full temperature range (note 2) i ref(dev) i k =10ma, r1=10k ? , r2=open (see note 1 and figure 2) 0.15 0.5 a minimum cathode current for regulation i k(min) v ka =v ref (see figure 1) 60 100 a off-state cathode current i k(off) v ref =0, v ka =18v (see figure 3) 0.02 0.1 a dynamic impedance (note 3) |z ka | v ka =v ref , f 1khz, i k =0.1ma~50ma (see figure 1) 0.25 0.4 ? notes: 1. full temperature ranges are: -40c~125c for ulvh431. 2. the deviation parameters v ref(dev) and i ref(dev) are defined as the differences between the maximum and minimum values obtained over the rated temper ature range. the average full-range temperature coefficient of the reference input voltage, v ref , is defined as: ref v ( ) c ppm = a 6 a ref ) dev ( ref t ? 10 ) ) c 25 = t ( v v ( where ? t a is the rated operating free-air temperature range of the device. v ref can be positive or negative, depending on whether minimum v ref or maximum v ref , respectively, occurs at the lower temperature. 3. the dynamic impedance is defined as: k ka ka i ? v ? = z when the device is operating with two external resi stors (see figure 2), the to tal dynamic impedance of the circuit is defined as: ) 2 r 1 r + 1 ( z i ? v ? = z ka ka
ulvh431 preliminary linear integrated circuit unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r103-115.b ? equivalent schematic
ulvh431 preliminary linear integrated circuit unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r103-115.b ? parameter measurement information i k(off) v in v o figure 3. test circuit for i k(off) utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
|
