參數(shù)資料
型號(hào): HT93214AT
廠商: Holtek Semiconductor Inc.
英文描述: 1-memory Tone/Pulse Dialer
中文描述: 1內(nèi)存音頻/脈沖撥號(hào)器
文件頁數(shù): 3/16頁
文件大小: 194K
代理商: HT93214AT
Pin Description
Pin Name
I/O
Internal
Connection
Description
C1~C3
R1~R4
I/O
CMOS
I/O
These pins along with the HKS form a 4 4 keyboard matrix which can perform key-
board input detection. When on-hook (HKS=high) all the pins are set high. While
off-hook the column group (C1~C3) is set low and the row group (R1~R4) remains
high for input detection.
Pressing a key connects a single row to a single column HKS and actuates the sys-
tem oscillator that results in a dialing signal output. If more than two keys are
pressedatthesametime,noresponseoccurs.Thekey-indebouncetimeis20ms.
X1
I
OSC
The system oscillator consists of an inverter, a bias resistor and the necessary load
capacitor on chip. Connecting a standard 3.579545MHz crystal or ceramic resona-
tor to the X1 and X2 terminals can implement the oscillator function. The oscillator is
turned off in the standby mode, and is actuated whenever a keyboard entry is de-
tected.
X2
O
XMUTE
O
NMOS
Open Drain
NMOS open drain structure pulled to VSS during dialing signal transmission. Other-
wise, it is an open circuit. This pin is used to mute the speech circuit when transmit-
ting the dial signal.
HKS
I
CMOS
This pin is used to monitor the status of the hook-switch and its combination with
HFI can control the PO pin output to make or break the line.
HKS=VDD: On-hook state (PO=low). Except for HFI (hand-free control input), other
functions are all disabled.
HKS=VSS: Off-hook state (PO=high). The chip is in the stand-by mode and ready
to receive the key input.
PO
O
NMOS
NMOS open drain output structure, which by receiving the HKS and HFO signals,
control the dialer so as to connect or disconnect the telephone line.
PO is pulled to VSS when HKS is high (on-hook) and HFO is low.
PO is an open circuit which make the line connection when HKS is low (off-hook) or
HFO is high.
During the off-hook state, this pin also outputs the dialing pulse train in pulse mode
dialing. While in the tone mode, this pin is always an open circuit.
MODE
I/O
CMOS
This is a tri-state input/output pin, used for dialing mode selection, either Tone
mode or Pulse mode, 10pps/20pps
MODE=VDD: Pulse, 10pps, M/B=1/2
MODE=Floating: Pulse, 20pps, M/B=1/2
MODE=VSS: Tone.
The MODE selection is checked each time a key input is received.
DTMF
O
CMOS
This pin is active only when the chip transmits tone dialing signals. Otherwise, it al-
ways outputs a low. The pin outputs tone signals to drive the external transmitter
amplifier circuit. The load resistor (to V
SS
) should not be less than 5k
load connected to V
DD
is not allowed.
and any DC
KT
O
NMOS
NMOS open drain structure for keytone output. It outputs 34ms of 600Hz tone burst
when any key is pressed in the pulse mode or when a function key is pressed in the
tone mode.
HFI
I
CMOS
Pulled-high, this pin is a Schmitt trigger input structure. Active low. Applying a nega-
tive going pulse to HFI can toggle the HFO once and hence control the hand-free
function. The pull-high resistance of HFI is about 200k
work is recommended for input debouncing.
typ. An external RC net-
HFO
O
CMOS
The HFO pin is a CMOS output structure. Its output is toggle- controlled by a nega-
tive transition on HFI pin. When HFO is high, the hand-free function is enabled and
PO outputs a high to connect the line.
The hand-free function can be released by an on-off-hook operation or by another
HFIinput.Refertothefunctionaldescriptionforthehand-freefunctionaloperation.
VDD
Positive power supply, 2.0V~5.5V for normal operation
VSS
Negative power supply, ground
MODEO
O
NMOS
NMOS open drain output pin pulled to VSS during tone output and is an open circuit
during pulse output.
HT93214 Series
Rev. 1.10
3
October 2, 2002
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HT93214B 制造商:HOLTEK 制造商全稱:Holtek Semiconductor Inc 功能描述:1-memory Tone/Pulse Dialer
HT93214BL 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Tone/Pulse Telephone Dialer
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HT93214BT 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Tone/Pulse Telephone Dialer
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