Holtek HT93214 Series User manual

HT93214 Series
1-memory Tone/Pulse Dialer
1 March 15, 2001
Features
·Operating Voltage: 2.0V~5.5V
·Low standby current
·Low memory retention current: 0.1mA
(Typ.)
·Tone/Pulse switchable
·32 (pulse)/31 (tone) digits for redialing
·Pause and P ®T key for PBX
·4´4 keyboard matrix
·3.58MHz crystal or ceramic resonator
·Hand-free control
·Pause, P ®T can be saved for redialing
·One-key redialing
·Keytone output
·Pause time: 2.2s
·Cascadable manual dialing after redialing
·Calibrated DTMF timing for redialing
·HT93214A: 16-pin DIP package
HT93214B/AT: 18-pin DIP package
General Description
The HT93214 are dialer series designed for low
cost telephone set applications with expand-
able features such as Lock function, keytone
and LCD display interface. With a 4´4 key-
board, it performs normal tone/pulse switch-
able dialing, and provides one-key redialing
function with a 32-digit memory for speed dial-
ing. An on-chip oscillator is built-in to work
with an external 3.58Mhz crystal or ceramic
resonator for accurate timing. The HT93214
provides 300ms (F1 key) and 600ms (F2 key) of
flash time; Tone dialing and 10pps, 20pps selec-
tion with 1/2 M/B ratio for pulse dialing.
Patent Number: 86474, 84545(R.O.C)

Selection Table
HT93214 series
Function
Item
Hand-
Free
Key
Tone Flash
Flash
Time
(ms)
Pulse
No.
Tone
Duration
(ms)
Inter
Tone
Pause (ms)
pps M/B
PKG
DIP
300mil
HT93214A Control 300/600 N 94 96 10/20 1/2 16
HT93214B ÖControl 300/600 N 94 96 10/20 1/2 18
HT93214AT ÖControl 300/600 N 94 96 10/20 1/2 18
Block Diagram
Pin Assignment
HT93214 Series
2 March 15, 2001
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
18
17
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
9
HKS
MODE
X1
X2
VSS
VDD
DTMF
XM UTE
R4
R3
R2
R1
C3
C2
C1
PO
HFO
HKS
MODE
X1
X2
VSS
VDD
DTMF
XM UTE
R4
R3
R2
R1
C3
C2
C1
PO
HFI 18
17
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
9
HKS
MODE
X1
X2
VSS
VDD
DTMF
XM UTE
MODEO
R4
R3
R2
R1
C3
C2
C1
PO
KT
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0 6'! "*
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0 6'! ") 6
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C1
R1
PO
Key
Colu n
FSM
Key
Function
Encoder
Encoder
C ontrol
WRM
C ounter
ADDRL
Key Row
SRAM
D ebounce
D ivider Clock
G enerator M/B
Flash/M ode
Ti er
C heck
Tone
Encoder
C onverter
HF
Tone
Out
Pulse
Out
X1
X2
DTM F
HFI
MODE
MODEO
XM UTE
C3
R4 Clock
C ontrol
Keytone
G enerator
HKS
HFO
KT

Keyboard Information
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 keyboard 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 system oscillator that results in a dialing signal out-
put. If more than two keys are pressed at the same time, no re-
sponse occurs. The key-in debounce time is 20ms.
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 resonator to the X1 and X2 ter-
minals can implement the oscillator function. The oscillator is
turned off in the standby mode, and is actuated whenever a key-
board entry is detected.
X2 O
XMUTE ONMOS
Open Drain
NMOS open drain structure pulled to VSS during dialing signal
transmission. Otherwise, it is an open circuit. This pin is used to
mute the speech circuit when transmitting 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.
HT93214 Series
3 March 15, 2001
2
5
8
0
3
6
9
#
F1
F2
P
R
C1 C2 C3
R4
R3
R2
R1 1
4
7
*/T
HKS

Pin Name I/O Internal
Connection Description
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 al-
ways an open circuit.
MODE I/O CMOS
This is a tri-state input/output pin, used for dialing mode selec-
tion, 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 sig-
nals. Otherwise, it always outputs a low. The pin outputs tone
signals to drive the external transmitter amplifier circuit. The
load resistor (to VSS) should not be less than 5kWand any DC
load connected to VDD is not allowed.
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 negative going pulse to HFI can toggle the HFO
once and hence control the hand-free function. The pull-high re-
sistance of HFI is about 200kWtyp. An external RC network is
recommended for input debouncing.
HFO O CMOS
The HFO pin is a CMOS output structure. Its output is toggle-
controlled by a negative 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 opera-
tion or by another HFI input. Refer to the functional description
for the hand-free functional operation.
VDD ¾¾ Positive power supply, 2.0V~5.5V for normal operation
VSS ¾¾ Negative power supply
MODEO O NMOS NMOS open drain output pin pulled to VSS during tone output
and is an open circuit during pulse output.
HT93214 Series
4 March 15, 2001

Approximate internal connection circuits
Absolute Maximum Ratings
Supply Voltage.................................-0.3V to 6V Storage Temperature.................-50°Cto125°C
Input Voltage .................VSS-0.3V to VDD+0.3V Operating Temperature ..............-20°Cto75°C
Note: These are stress ratings only. Stresses exceeding the range specified under "Absolute Maxi-
mum Ratings" may cause substantial damage to the device. Functional operation of this device
at other conditions beyond those listed in the specification is not implied and prolonged expo-
sure to extreme conditions may affect device reliability.
Electrical Characteristics FOSC=3.5795MHz, Ta=25°C
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VDD Conditions
VDD Operating Voltage ¾¾ 2¾5.5 V
IDD Operating Current 2.5V
Pulse Off-hook
Keypad entry
¾0.2 1 mA
Tone ¾0.6 2 mA
ISTB Standby Current 1V On-hook, no load
No entry ¾¾ 1mA
VRMemory Retention Voltage ¾¾ 1¾5V
IRMemory Retention Current 1V On-hook ¾0.1 0.2 mA
VIL Input Low Voltage ¾¾ VSS ¾0.2VDD V
VIH Input High Voltage ¾¾
0.8VDD ¾VDD V
HT93214 Series
5 March 15, 2001
NMOS OUT
VDD
CMOS IN/OUT CMOS OUT
CMOS IN
Pull-Low
CMOS IN
P u ll-H ig h
CMOS IN
OSCILLATOR
X1 X2
EN
10M
20P 10P
VDD

Symbol Parameter Test Conditions Min. Typ. Max. Unit
VDD Conditions
IXMO XMUTE Leakage Voltage ¾VXMUTE=12V
No entry ¾¾ 1mA
IOLXM XMUTE Sink Current 2.5V VXMUTE=0.5V 1¾¾
mA
IHKS HKS Pin Input Current 2.5V VHKS=2.5V ¾0.1 mA
RHFI HFI Pull- High Resistance 2.5V VHFI=0V ¾200 ¾kW
IOH1 Keypad Pin Source Current 2.5V VOH=0V -4¾-40 mA
IOL1 Keypad Pin Sink Current 2.5V VOL=2.5V 200 400 ¾mA
IOH2 HFO Pin Source Current 2.5V VOH=2V -1¾¾
mA
IOL2 HFO Pin Sink Current 2.5V VOL=0.5V 1¾¾
mA
IOL3 MODEO Sink Current 2.5V VOL=0.5V 0.6 3.5 ¾mA
TFP Pause Time After Flash 2.5V ¾¾
800 ¾ms
TRP One-key Redialing Pause
Time 2.5V ¾¾
800 ¾ms
FOSC System Frequency ¾¾ ¾
3.58 ¾MHz
TDB Key-in Debounce Time 2.5V ¾¾
20 ¾ms
TBRK Break Time For One-key
Redialing 2.5V ¾¾
2.2 ¾s
THKDL Off-hook Delay Time 2.5V 10pps ¾800 ¾ms
20pps ¾500 ¾
Pulse Mode Electrical Characteristics FOSC=3.5795MHz, Ta=25°C
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VDD Conditions
IPOH PO Output Source Current 2.5V VOH=2V -0.2 ¾¾
mA
IPOL PO Output Sink Current 2.5V VOL=0.5V 0.2 0.6 ¾mA
PRPulse Rate ¾
MODE pin is
connected to VDD
¾10 ¾pps
MODE pin is opened ¾20 ¾
M/B Make/Break Ratio ¾¾ ¾ 33:66 ¾%
TPDP Pre-digit-pause Time ¾
M/B=33:66 (10 pps) ¾33 ¾ms
M/B=33:66 (20 pps) ¾17 ¾
HT93214 Series
6 March 15, 2001

Symbol Parameter Test Conditions Min. Typ. Max. Unit
VDD Conditions
TIDP Inter-digit-pause Time ¾
10 pps ¾800 ¾ms
20 pps ¾500 ¾
TMPulse Make Duration ¾
10 pps, M/B=1/2 ¾33.3 ¾ms
20 pps, M/B=1/2 ¾16.7 ¾
TBPulse Break Duration ¾
10 pps, M/B=1/2 ¾66.6 ¾ms
20 pps, M/B=1/2 ¾33.3 ¾
TPPause Time ¾¾ ¾
2.2 ¾s
Tone Mode Electrical Characteristics FOSC=3.5795MHz, Ta=25°C
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VDD Conditions
VTDC DTMF Output DC Level ¾No load 0.45VDD ¾0.7VDD V
ITOL DTMF Sink Current 2.5V VDTMF=0.5V 0.1 ¾¾
mA
VTAC DTMF Output AC Level ¾Row group,
RL=5kW0.12 0.155 0.18 Vrms
RLDTMF Output Load 2.5V THD£-23dB 5¾¾kW
ACR Column Pre-emphasis 2.5V Row group=0dB 1 2 3 dB
THD Tone Signal Distortion 2.5V RL=5kW¾-30 -23 dB
TTMIN Minimum Tone Duration ¾Auto-redial ¾94 ¾ms
TITPM Minimum Inter-Tone Pause ¾Auto-redial ¾96 ¾ms
THD (Distortion) (dB) = 20 log ( V1 V2 .... Vn
22 2
+++ /Vi Vh
22
+)
Vi, Vh: Row group and column group signals
V1, V2, ... Vn: Harmonic signals (BW=300Hz~3500Hz)
HT93214 Series
7 March 15, 2001

HT93214 Series
8 March 15, 2001
Functional Description
Keyboard matrix
C1~C3, HKS and R1~R4 form a keyboard ma-
trix. Together with a standard 4´4 keyboard,
the keyboard matrix is used for dialing entries.
The keyboard arrangement of the HT93214 se-
ries is shown in the Keyboard Information.
Tone frequency
Tone
Name
Output Frequency (Hz) % Error
Specified Actual
R1 697 699 +0.29%
R2 770 766 -0.52%
R3 852 847 -0.59%
R4 941 948 +0.74%
C1 1209 1215 +0.50%
C2 1336 1332 -0.30%
C3 1477 1472 -0.34%
Note: % Error does not contain the crystal fre-
quency drift
Dialing specification selection
·The specifications are selected by the MODE
pin.
MODE Tone/Pulse Dial Rate M/B Ratio
VDD Pulse 10pps 1/2
VSS Tone ¾¾
Floating Pulse 20pps 1/2
·The MODE pin status is checked whenever a
digit key is pressed, however the M/B and
pulse rate are determined at the first key en-
try.
Hand-free function operation
·When HFO is low, a falling edge triggers the
HFI, enabling the Hand-free function (HFO
becomes high).
·Reset Hand-free function
When HFO is high, the Hand-free function is
enabled and can be reset by:
¨Off-hook
¨Applying a falling edge to HFI
·Hand-free function table
Current State Next State
Hook SW HFO Input HFO Dialing?
¾Low HFI ¯High Yes
On hook High HFI ¯Low No
Off hook High HFI ¯Low Yes
On hook ¾of
off-hook Low Yes
Off hook Low on hook Low No
Off hook High on hook High Yes
Flash
Two flash keys are provided, namely F1, F2 for
both series. All the flash key function as control
key with different break duration. Whenever a
flash key is pressed the PO pin will be forced
low for a TFduration and the transmission of
the new digit key inputs will be further delayed
foraT
FP after TF. See the following table for
flash duration selection.
Item F1 F2
HT93214 300ms 600ms
Key definition
·0,1,2,3,4,5,6,7,8,9 keys
These are dialing number input keys for
both the pulse mode and the tone mode oper-
ation.
·*/T
This key executes the P®T function and
waits a TP®Tduration in the pulse mode. On
the other hand, the */T key executes the *
function in the tone mode. The */T key will oc-
cupy one memory digit in either tone or pulse
mode.

HT93214 Series
9 March 15, 2001
·#
This is a dialing signal key for the tone mode
only, no response in the pulse mode.
·F1, F2
Pressing one of the flash keys will force the PO
pin to become low for the TFduration. To
transmit the dial signals of the key input that
are entered after the F key, a wait period TFP
(sec) after PO pin returns from low is pro-
vided.
·P
Pause key. The execution of this key pauses
the output for the TPduration (2.2s).
·R
Redial key. It executes redialing as well as
one-key redial function.

Keyboard Operation
The following operations are described under an on-off- hook or on-hook condition with the hand-free
active condition.
HT93214 Series
10 March 15, 2001
Keyboard input: D 1 D 2 ... D n
- Pulse ode
(a ) w ith o u t */T
D ialing output: D 1 D 2 ... D n
RM: D1 D2 ... Dn
(b ) w ith */T
D ia lin g o u tp u t: D 1 D 2 ... D n T
P®T
D n + 1 ... D
R M : D 1 D 2 ... D n * /T D n + 1 ... D
Tone
Pulse
·
N o r a l d ia lin g
K e y b o a rd in p u t: D 1 D 2 ... D n */T D n + 1 ...
D
(a ) w ith o u t */T
D ialing output: D 1 D 2 ... D n
RM: D1 D2 ... Dn
(b ) w ith */T
D ia lin g o u tp u t: D 1 D 2 ... D n * D n + 1 ... D
R M : D 1 D 2 ... D n * D n + 1 ... D
-
Tone ode
(a ) w ith o u t */T
D ialing output: D 1 D 2 ... D n
R M : U nchanged
R M c o n te n t: D 1 D 2 ... D n
(b ) w ith */T
D ia lin g o u tp u t: D 1 D 2 ... D n T
P®T
D n + 1 ... D
R M : U nchanged
R M c o n te n t: D 1 D 2 ... D n * /T D n + 1 ... D
D ialing output: D 1 D 2 ... D n
R M : U nchanged
R M c o n te n t: D 1 D 2 ... D n
(b ) w ith */T
D ia lin g o u tp u t: D 1 D 2 ... D n * D n + 1 ... D
R M : U nchanged
R M c o n te n t: D 1 D 2 ... D n * /T D n + 1 ... D
- Pulse ode -
Tone ode
Pulse
Tone
·
R edial
K e y b o a rd in p u t: D 1 D 2 ... D n */T D n + 1 ...
D
(a ) w ith o u t */T
Keyboard input: D 1 D 2 ... D n
Keyboard input: R
Keyboard input: R
Keyboard input: R
Keyboard input: R
N ote: The axi u capacity of the R M e ory is 32 digits. W hen ore than 32 digits are entered,
the signal is trans itted but the redial function is inhibited.