l9997nd dual half bridge driver half bridge outputs with typical r on = 0.7 w output current capability 1.2a operating supply voltage range 7v to 16.5v supply overvoltage protection function for v vs up to 40v very low quiescent current in standby mode < 1 m a cmos compatible inputs with hys- teresis output short-circuit protection thermal shutdown real time diagnostic: thermal over- load, overvoltage description the l9997nd is a monolithic integrated driver, in bcd technology intended to drive various loads, including dc motors. the circuit is optimized for automotive electronics enviromental conditions. april 1999 ? out1 out2 gnd in1 in2 en diag 5v 10 1 12 9 2 19 11 4...7, 14...17 vs vs vs vs protection functions reference bias driver 1 driver 2 enable m block diagram so20 (12+4+4) ordering numbers: l9997nd L9997ND013TR multipower bcd technology 1/9
absolute maximum ratings symbol parameter value unit v vsdc dc supply voltage -0.3 to 26 v v vsp supply voltage pulse (t < 400ms) 40 v i out dc output current 1.8 a v in1,2 dc input voltage -0.3 to 7 v v en enable input voltage -0.3 to 7 v v diag dc output voltage -0.3 to 7 v i out dc output short-circuit current -0.3v < v out < v s + 0.3v internally limited i diag dc sink current -0.3v < v dg < 7v internally limited thermal data symbol parameter value unit t jts thermal shut-down junction temperature 165 c t jtsh thermal shut-down threshold hysteresis 25 k r th j-amb thermal resistance junction-ambient (1) 50 k/w r th j-pins thermal resistance junction-pins 15 k/w (1) with 6cm 2 on board heatsink area. v s out2 n.c. gnd gnd gnd gnd n.c. in2 in1 n.c. gnd gnd gnd gnd n.c. out1 n.c. 1 3 2 4 5 6 7 8 9 18 17 16 15 14 12 13 11 19 10 20 en diag d95at166 pin connection (top view) pin functions n. name function 1 vs supply voltage 2 out2 channel 2: push-pull power output with intrinsic body diode 3, 8, 13, 18,20 nc nc: not connected 4 to 7, 14 to 17 gnd ground: signal - and power - ground, heat sink 9 in2 input 2: schmitt trigger input with hysteresis (non-inverting signal control) 10 en enable: low or not connected on this input switches the device into standby mode and the outputs into tristate 11 diag diagnostic: open drain output that switches low if overvoltage or overtemperature is detected 12 in1 input 1: schmitt trigger input with hysteresis (non-inverting signal control) l9997nd 2/9
electrical characteristics (7v < v s < 16.5v; -40c < t j < 150c; unless otherwise specified.) symbol parameter test condition min. typ. max. unit i vs_sb quiescent current in standby mode v en < 0.3v; v vs <16.5v; t j < 85(*) v en = 0; v vs = 14.5v; t j = 25c <1 <1 90 10 m a m a i vs supply current en = high, i out1,2 = 0 2 6 ma v enl low enable voltage 1.5 v v enh high enable voltage 3.5 6 v v enthh enable threshold hysteresis 1 v i en enable input current v en = 5v 85 250 m a v in1,2l low input voltage 1.5 v v in1,2h high input voltage 3.5 v v in1,2thh input threshold hysteresis 1 v i in1,2 input bias current v in = 0 v in = 5v, en = high -3 2 0 10 1 50 m a m a r on out1,2 on-resistance to supply or gnd i out = 0.8a; v vs = 7v; t j = 125c i out = 0.8a; v vs = 12v; t j = 125c i out = 0.8a; v vs = 12v; t j = 25c 1.2 1.1 0.7 2.8 2.25 w w w |i out1,2 | output current limitation 1.2 1.6 2.2 a v diag diagnostic output drop i diag = 0.5ma, en = high overvoltage or thermal shut- down 0.6 v v vsovth supply overvoltage threshold 17 19 21 v t onlh turn on delay time see fig. 2; v vs = 13.5v measured with 93 w load 50 150 m s t onhl 30 150 m s t offhl turn off delay time 10 100 m s t offlh 220 m s t dhl rising delay time 115 250 m s t dlh falling delay time 115 250 m s t rhs rise time 30 100 m s t rls 60 150 m s t fhs fall time 25 100 m s t fls 50 150 m s * tested at 125c and guaranteed by correlation functional description the l9997nd is a motor driver two half-bridge outputs, intended for driving dc motors in automo- tive systems. the basic function of the device is shown in the table 1. table 1. table function. status en in1 in2 out1 out2 diag note 1 l x x tristate tristate off standby mode 2 h h h src src off recommended for braking 3 h h l src snk off 4hlhsnksrcoff 5 h l l snk snk off 6 h x x tristate tristate on overvoltage or overtemperature l9997nd 3/9
the device is activated with enable input voltage high. for enable input floating (not connected) or low the device is in standby mode. very low quiescent current is defined for v en < 0.3v. when activating or disactivating the device by the en- able input a wake-up time of 50 m s is recom- mended. for braking of the motor the status 2 is recom- mended. the reason for this recommendation is that the device features higher threshold for ini- tialisation of parasitic structures than in state 5. the inputs in1, in2 features internal sink current generators of 10 m a, disabled in standby mode. with these input current generators the input level is forced to low for inputs open. in this condition the outputs are in snk state. the circuit features an overvoltage disable func- tion referred to the supply voltage v vs . this func- tion assures disabling the power outputs, when the supply voltage exceeds the over voltage threshold value of 19v typ. both outputs are forced to tristate in this condition and the diagnos- tic output is on. the thermal shut-down disables the outputs (tris- tate) and activates the diagnostic when the junc- tion temperature increases above the thermal shut-down threshold temperature of min. 150c. for the start of a heavy loaded motor, if the motor current reaches the max. value, it is necessary to respect the dynamical thermal resistance junction to ambient. the outputs out1 and out2 are pro- tected against short circuit to gnd or v s , for sup- ply voltages up to the overvoltage disable thresh- old. the output power dmos transistors works in lin- ear mode for an output current less than 1.2a. in- creasing the output load current (> 1.2a) the out- put transistor changes in the current regulation mode, see fig.6, with the typical output current value below 2a. the src output power dmos transistors requires a voltage drop ~3v to activate the current regulation. below this voltage drop is the device also protected. the output current heat up the power dmos transistor, the r dson in- creases with the junction temperature and de- creases the output current. the power dissipation in this condition can activate the thermal shut- down . in the case of output disable due to ther- mal overload the output remains disabled untill the junction temperature decreases under the thermal enable threshold. permanent short circuit condition with power dis- sipation leading to chip overheating and activation of the thermal shut-down leads to the thermal os- cillation. the junction temperature difference be- tween the switch on and off points is the ther- mal hysteresis of the thermal protection. this hysteresis together with the thermal impedance and ambient temperature determines the fre- quency of this thermal oscillation, its typical val- ues are in the range of 10khz. the open drain diagnostic output needs an exter- nal pull-up resistor to a 5v supply. in systems with several l9997nd the diagnostic outputs can be connected together with a common pull-up re- sistor. the diag output current is internally lim- ited. fig. 1 shows a typical application diagram for the dc motor driving. to assure the safety of the cir- cuit in the reverse battery condition a reverse pro- tection diode d 1 is necessary. the transient pro- tection diode d 2 must assure that the maximal supply voltage v vs during the transients at the v bat line will be limited to a value lower than the absolute maximum rating for v vs . m v s 5v c s in1 in2 gnd diag1 control logic 47k w idiag1 iin1 iin2 ien en d 2 v bat d 1 i s l9997nd out1 im vm iout1 iout2 out2 gnd figure 1: application circuit diagram. l9997nd 4/9
en in1 in2 diag out1 out2 standby mode operating mode overtemperature or overvoltage standby mode t rf t t dlh t dhl t offlh tr i s t a t e 90% t r 90% 50% 10% f t 10% t onhl tr i s t a t e t dhl t offhl t dlh t dhl t dlh t dhl tristate tristate tristate tristate t onlh t dlh figure 2. timing diagram. figure 3. typical r on - characteristics of source and sink stage l9997nd 5/9
figure 5. on-resistance versus supply voltage. figure 4. quiescent current in standby mode versus supply voltage. l9997nd 6/9
out1 out2 in1 in2 en gnd diag 10k w 200nf 100f 12v v en 15 w 5v in1 v in2 v l9997nd 15 w vs figure 7. test circuit. figure 6. i out versus v out (pulsed measurement with t on = 500 m s, t off = 500ms). l9997nd 7/9
l9997nd 8/9
information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsib ility for the cons equences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specification mentioned in this pu blication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectron ics products are not authorized for use as critical components in life support devices or systems without express written approval of stmicr oelectronics. the st logo is a registered trademark of stmicroelectronics ? 1999 stmicroelectronics C printed in italy C all rights reserved stmicroelectronics group of companies australia - brazil - canada - china - france - germany - italy - japan - korea - malaysia - malta - mexico - morocco - the neth erlands - singapore - spain - sweden - switzerland - taiwan - thailand - united kingdom - u.s.a. http://www.st.com l9997nd 9/9
|
