UM9151 UMC | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 5
Technical content
Features
® Direct telephone line operation @ 18 lead dual-in-line package. @ 4x3 matrix single contact keyboard = Redial with either * or #key i © Supply voltage range 2.5V to 5V = Dialer reset for line power break > 200 msec. ® Inexpensive RC oscillator ® Pin selectable inter-digital pause (IDP) ® Low power standby mode for redial '® Pin selectable make/break (M/B) ™ 22 digit capacity for redial ™ High speed test capability | General Description The UM9151 pulse dialer is a monolithic CMOS integrated the line; the other mutes the receiver. circuit which converts pushbutton inputs to a series of pulses suitable for telephone dialing, It is intended CMOS technology used to produce this device results to replace mechanical telephone dialers and can operate in very low power consumption and enables easy inter- directly from the telephone lines. The pulse dialer facing with a variety of telephones with high noise function is implemented using two outputs; one pulses immunity and few external components. | Pin Configuration Block Diagram =-F =! . rest] 1 why “ Hb aa C]3 ie [_] 2 . meer ra C4 if] cl 3 Yoo [_] 5 um9151 14 [7] Vss I] [ iJ cxi C] 6 13 wre = pC se] | ck ([]7 12) mR | Lz] j ce [Je [0 — | 17
© . UM9151 Absolute Maximum Ratings* *Comments Ratings” may cause permanent damage to the device. This . at these or any other conditions above those indicated in
Electrical Characteristics
(Vgg = OV, Vp = 3.5V, Top = 25°C unless otherwise specified) De Supply Vottove ef-fe{y fo Supply Current Standby HA | Vp = 2.5V With pins 1, 10, and 11 connected. Operating HA | Vop =5V_ Pin Gis open. Keyboard Contact R__ | Resistance 1 | ka C | Capacitance 30 | pF Key Input Debounce Time fert-[-[m fins | Mask Sink Current js] - | - | | Yop =28V Vp =08V [me | Mask Driving Carent [| -|- [| Woo =28¥ Yon [tis [eresinccurans [so | - | - [om | Yoo =28V Yo“ 08V Line Leokene Corent |---| [| Yoo “ 8Y vo" sv Tone Driving Carent [20] | - [| Yoo = 28V vo=2v Oscillation Frequency | - [| - [| Per typical application, Voy =3.5V AF/F - =25~ - Frequency Veriation Le | -[s{ + | Woo =2.5~S8N. (Faa~Faslifas vs Volta Are ” effet =| Yop =3878¥. fevfealts Variati Pe rip | Frequency Veriation 4 44 er typical application per Lot Vop =3.5V 500 mesaetess [- |e] [| eee 1-8
43) uMc um9151 NEE Timing Diagram ee a = O8CRLATOR, ——S ng pgie-= === =f UMM = -===-----s ents ---~ -=--- a TTT TTF nnn 08 a Lo oo at nn mee Key INPUT ort 2 oir REDIAL oer {Mn oe 7 T joe bored | Pin Description test Dialing rate = 10pps when connected to Vpp. (normal) Dialing rate = 600pps when connected to Veg. (high speed test) 18,2,3,4 Ry, Ra, Ra, Re Keyboard inputs. | KI, CK, CK These pins are connected to an RC oscillator. (clock frequency control) ! le | oP Dialing pulse output. The output stage is an N-channel open drain device. we M/B = 33'/3/66%s if connected to Vop, M/B = 40/60 if connected to Veg. : IDP = 500ms if connected to Vpn. IDP = 800ms if connected to Vg. OrrnooklOFt Hook input Mure MUTE out mute telephone speech cuit ee tee a 1-9
y ®ume um9151 Functional Description LOW. If the AK input is taken to logic HIGH for a period of less than 200 msec and then returned to logic Oscillator LOW, no action is taken and the dialer will continue to function. The oscillator consists of two inverters and external com- Ponents which control the oscillation frequency. The 14 it ig taken to logic HIGH for @ period greater than 200 circuit is. sufficiently versatile to allow a variety of — insoc. oscillator and any dialing sequence will cease, component combinations. The oscillation circuit detailed i, internal counters will be reset, though the contents below, has an oscillation frequency of 18KHz for 10 oF the RAM will be unaffected. Taking the input back ps dialing rate. to logic LOW will restart the keyboard scan and dialing sequence and the dialer will wait for a data entry. DP cKI > fad > cK The loop-disconnect dial pulses appear at the DP output. 0 ° The output stage consists of an N-channel open drain device sinking current to Vsg. During a dial pulse break 1soxa 1sope Period the output device is switched on and during the make period and IDP the output device is switched off. The output drives an external bipolar transistor that sequentially opens the telephone loop a number of oxcillator circuit times equal to the input digit selected. For example, key 7 will generate 7 loop current breaks. 4.x 3 Matrix Mode MUTE A pulse to logic low is sequentially switched around the The MUTE output is used to control the muting of the three keyboard scan outputs and requires 5 ms for a telephone network during out dialing. A logic HIGH complete scan cycle, When a key is depressed, the pulse indicates that the telephone is to be muted, the transi- (logic low) appears on one of the four keyboard inputs tion to logic HIGH occuring immediately on recognition (provided with on-chip pull up resistors to logic high). of a key depression. Following key depression and 6.7 ms antibounce period, the data is entered to RAM. Before a second key de- —_—Redialing pression can be recognized, the first key must be released and a full antibounce period completed without @ pulse ‘The Keyboard inputs are accepted at an asynchronous appearing on any input. If two or more keys are depressed _-—*'@t®, load into a first-in-first-out RAM, If the call is not during the same scan cycle, the data will be rejected and —«SUCcessful, it can be redialed at a later time by pressing another full antibounce period must be completed without _the redial key * or #, and the correct number of pulses a pulse appearing on any of the inputs before the next _Degins to read out. For example, dialing 0123 45 6 key depression is recognized, and onhook a period of valid redialing, when off-hook again, pressing the redial key * or #, RAM will read out mR 0 1.23456. Since UM9151 allows only one key to be entered before pressing the redial key, it is suitable for External circuitry connected to HK input is used to use in a PABX system. For example, dialing 0123456 indicate whether the telephone handset is on-hook or and orhook a period of valid redialing, when off-hook off-hook, these two states being represented by logic again, pressing any key “N’ (N =O, 1, 2,....9) except HIGH, logic LOW respectively. If power is present on * or #, then pressing the redial key, RAM will read out the “dialer, this input should normally be held at logic 1234.56. 1-10
® UmM9151 Typical Application ‘An example of loop disconnect UM9151 interface / Py E we on az fins o i ae 2NA a oPeecH wy o ‘TEST Vy KR Yoo 2 ‘00 o wore { CEE} —y " tor [119 800MS l=] et Re UM9151 SW29 Yoo poo ee aoe Oe Eh} —4 wwe Po omen? ma c3 cz cy KH CK OK ss ale Ro ROS a0re0 | o 1, Loop Disconnect Interface: Q;, Q2, Rs, Ra, Rs and DP BG1: IN4001x4 i Q; and O, act 2s switching transistors, DP is the dial pulse output which drives Q, transistor ae ater t on and off as make and break, Re pulls up the DP output, Rs protects the Qy transistor | Os: 2N65401 during break period and Rg limits the base current of Qy Qy: 2N5AOT . Ry: 22M i Rz: 220K 2. Power supply: Ri, Ra. Re, Rr, Qs, Q4,D1,D2 and Cy Be: Ok | A current source is constructed by Rg, R7, Q3 and Qy. It can supply @ 600 HA constant Re: 3K3 l current to UM9151 which is indpendent from the line power variation. Dz can protect Re: he | this chip under 5.6V. Ra, the power intial loop, supplies the intial power at oftthook | Rg: 220K instant, Ry, the data retention loop, retains the memory during on-hook. Bs: 270K 7 | _ Ch! 47uF/IOWV 3. Oscillator: CKI, CK, CK, Ro, Ryo and Cz C,: 150pF The oscillation frequency is 18 KHz for 10 pps dialing. BL I NeIOoW 20 | 1-11