description the ht8a977b and ht8a978b provide complete control functions to the remote-controlled toy. the ht8a977b has five input pins corresponding wi th the five function buttons i.e, forward, backw ard, rightward, leftward and turbo. the encoding ci rcuit in the ht8a977b sends digital codes to t he two output pins so and sc. the digital codes co rrespond to the definite function buttons or thei r combinations. the so and sc outputs are used in wireless and infra-red applications respectively. the ht8a978b has five output pins corresponding with the five actions. the received signals are amplified by the three-stage amplifier, and then the appropriate amplified signals are sampled, fault-tolerant ly checked and decoded to control the actions of t he remote-controlled toy. there is an internal oscillator in the ht8a977b and 978b respectively. by adding an external resistor convenient ly, the oscillator will be constructed. the oscill ator frequency can be adjusted by the external resistor. the relative error between the frequencies of the two on-chip oscillators in the ht 8a977b and ht8a978b must be less than 25%. the auto-power-off func tion is achieved by an internal counter (977b). the pc output is used to control on/off state of the external power supply. press on any function button will wake up the chip promptly. features ? ht8a977b works as encoder and ht8a978b works as decoder ? five pins for five control functions ? operating power-supply voltage: 2.5v to 5.0v (978b), 1.8v to 5.0v(977b) ? auto-power-off and oscillation-off if no press on any button (977b) ? press on any button to wake up (977b) ? one output pin used for external power control (977b) ? on-chip oscillator with an external resistor ? on-chip reversing amplifiers (978b) ? low operating current ? few external components needed ? package: 14-pin dip, 14-pin soic, 16-pin dip, 16-pin soic, die form and wafer form ordering information part no. package ht8a977bpe lead free 14-pin dip ht8a977bwe lead free 14-pin soic ht8a978bpe lead free16-pin dip HT8A978BLWE lead free 16-pin soic 1 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
block diagram block diagram of 977b block diagram of 978b pin configuration pt8a977bp/977bw pt8a978bp/978blw 2 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
pin/pad description pin/pad description of 977b pin no. pin/pad name description 1 right with pull-up resistor, rightwa rd function selected if this pin connected to gnd. 2 gnd negative power supply 3 backward with pull-up resistor, ba ckward function selected if this pin connected to gnd. 4 forward with pull-up resistor, fo rward function selected if this pin connected to gnd. 5 turbo with pull-up resistor, tur bo function selected if this pin connected to gnd. 6 sc output pin of the encodi ng signal with carrier frequency 7 so output pin of the encodi ng signal without carrier frequency 8 vcc positive power supply 9 pc power control output pin 10 osco oscillator output pin 11 osci oscillator input pin 12 off with pull-up resistor, this pi n is used to shut down the external power supply. 13 left with pull-up resistor, leftw ard function selected if this pin connected to gnd. 3 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
pin/pad description of 978b pin no. pin/pad name description 1 vo2 output pin for the amplifier 2 2 gnd negative power supply 3 si input pin of the encoding signal 4 osci oscillator input pin 5 osco oscillator output pin 6 right rightward output pin 7 left leftward output pin 8 rd with pull-up resistor, rightward function disabled if this pin connected to gnd. 9 ld with pull-up resistor, leftward function disabled if this pin connected to gnd. 10 backward backward output pin 11 forward forward output pin 12 turbo turbo output pin 13 vcc positive power supply 14 vi1 input pin for the amplifier 1 15 vo1 output pin for the amplifier 1 16 vi2 input pin for the amplifier 2 maximum ratings (above which the useful life may be im paired. for user guidelines, not tested) note: stresses greater than those listed under maxi-mum ratings may cause permanent damage to the device. this is a stress rating only and func-tional operation of th e device at these or any other conditions above those indicated in the operational sections of this specification is not implied. expo-sure to absolute maximum rating conditions for ex-tended periods may affect reliability. storage temperature .......................................................... -25 o c to +85 o c ambient temperature with power applied .......................... -10 o c to +40 o c supply voltage to ground potential (inputs & v cc only) ...... -0.5 to +6.0v supply voltage to ground potential (o utputs & d/o only) ... -0.5 to +6.0v dc input voltage .................................................................. -0.5 to +6.0v dc output current .......................................................................... 20ma power dissipation ........................................................................ 500mw 4 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
dc electrical charateristics dc electrical charat eristics of 977b parameters description test condition min. type max. units v cc operating voltage 1.8 4.0 5.0 v i cc supply current output unloaded 150 ua i stb stand-by current off state 5 ua v il input low voltage guaranteed logic low level 0.8 v v ih input high voltage guaranteed logic high level 3.0 v i il input low current pin 1, 3, 4, 5, 13 vih = 0v, on state -60 ua i ih input high current pin 1, 3, 4, 5, 13 vih = 4v, on state 10 ua i i input current pin 11 vih = 0 ~ 4v, on state 10 ua i ol output low current vout = 0.5 v 150 ua i oh output high current pin 6, 7, 9 vout = 3.5 v -1.0 ma pin 10 vout = 3.5 v -500 ua note: over the operating rating, 0 o c t a 70 o c, v cc = 4v dc electrical charat eristics of 978b parameters description test condition min. type max. units v cc operating voltage 2.5 4.0 5.0 v i cc supply current output unloaded 1.2 ma i stb stand-by current off state 10 ua v il input low voltage guaranteed logic low level 0.8 v v ih input high voltage guaranteed logic high level 3.0 v i il input low current pin 3, 8, 9 v il = 0v, on state l -60 ua i ih input high current pin 3 v ih = 4v, on state 60 ua input high current pin 8, 9 v ih = 4v, on state 10 ua i i input current pin 14, 16 v ih = 0 ~ 4v, on state 10 ua i ol output low current pin 1, 15 v out = 0.5 v 200 ua pin 5 v out = 0.5 v 500 ua pin 6, 7, 10, 11, 12 v out = 0.5 v 1 ma i oh output high current pin 1, 15 v out = 3.5 v -200 ua pin 5 v out = 3.5 v -500 ua pin 6, 7, 10, 11, 12 v out = 2.5 v -600 ua note: over the operating rating, 0 o c t a 70 o c, v cc = 4v 5 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
ac electrical characteristics ac electrical charac teristics of 977b parameters description test condition min. type max. units fosc oscillator frequency * t a = 25oc, r = 200 k ? 102 128 154 khz fmax-fmin oscillator frequency fluctuation t a =25oc, v cc = 1.8 ~ 5v 15 khz tfun cycle time of function code f osc = 102 to 154 khz 0.8 1 1.2 ms tsta cycle time of start code f osc = 102 to 154 khz 1.6 2 2.4 ms fcsc carrier frequency of sc pin f osc = 102 to 154 khz 51 64 77 khz note: over the operating rating, 0 o c t a 70 o c, v cc = 4v * the relative error between th e frequencies of the two on-chip oscillators in th e ht8a977b and ht8a978b must be less than +25%. ac electrical charac teristics of 978b parameters description test condition min. type max. units f osc oscillator frequency * t a = 25 o c, r = 200 k ? 102 128 154 khz f max -f min oscillator frequency fluctuation - 978b t a =25 o c, v cc =2.5 ~ 5v 15 khz oscillator frequency fluctuation - 978bl t a =25 o c, v =2.0 ~ 5v 10 khz v si si pin receive sensitivity (vpp) guaranteed effective decoding 300 mv t fun cycle time of function code f osc = 128 khz 0.75 1 1.25 ms t sta cycle time of start code f osc = 128 khz 1.5 2 2.5 ms note: over the operating rating, 0 o c t a 70 o c, v cc = 4v * the relative error between the frequencies of the two on-chip oscillators in the ht8a977b and ht8a978b must be less than +25%. 6 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
application circuits typical application of ht8a 977b for transmit circuit 7 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
typical application of ht8a978 b/978bl for transmit circuit 8 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
mechanical information 14-pin soic 14-pin dip 9 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
16-pin soic 16-pin dip 10 of 10 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification ht8a977
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