|
|
PDF AM79R70JC Data sheet ( Hoja de datos )
| Número de pieza | AM79R70JC | |
| Descripción | Ringing Subscriber Line Interface Circuit | |
| Fabricantes | Advanced Micro Devices | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AM79R70JC (archivo pdf) en la parte inferior de esta página. Total 17 Páginas | ||
|
No Preview Available !
PRELIMINARY
Am79R70
Ringing Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
s Ideal for ISDN-TA and set top applications
s On-chip ringing with on-chip ring-trip detector
s Low standby state power
s Battery operation:
— VBAT1: –40 V to –67 V
— VBAT2: –19 V to VBAT1
s On-chip battery switching and feed selection
s On-hook transmission
s Polarity reversal option
s Programmable constant-current feed
s Programmable Open Circuit voltage
s Programmable loop-detect threshold
s Current gain = 1000
s Two-wire impedance set by single component
s Ground-key detector
s Tip Open state for ground-start lines
s Internal VEE regulator
(no external –5 V power supply required)
s Two on-chip relay drivers and snubber circuits
BLOCK DIAGRAM
RTRIP1
RTRIP2
A(TIP)
HPA
HPB
B(RING)
VBAT2
VBAT1
Two-Wire
Interface
Switch
Driver
Relay
Driver
Relay
Driver
Ring-Trip
Detector
Ground-Key
Detector
Off-Hook
Detector
Input Decoder
and Control
Signal
Transmission
Power-Feed
Controller
RYOUT2
RYE
RYOUT1
D1
D2
C1
C2
C3
E1
DET
RD
VTX
RSN
RINGIN
RDC
RDCR
RSGL
RSGH
B2EN
VCC VNEG BGND AGND/DGND
This document contains information on a product under development at Advanced Micro Devices. The information
is intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice.
Publication# 21776 Rev: B Amendment: /0
Issue Date: July 1998
1 page  
PIN DESCRIPTIONS
Pin Names
AGND/DGND
A(TIP)
B2EN
Type
Gnd
Output
Input
BGND
B(RING)
C3–C1
D1
D2
DET
Gnd
Output
Inputs
Input
Input
Output
E1 Input
HPA
HPB
RD
RDC
Capacitor
Capacitor
Resistor
Resistor
RDCR
RINGIN
RSGH
RSGL
RSN
—
Input
Input
Input
Input
RTRIP1
RTRIP2
RYE
RYOUT1
RYOUT2
VBAT1
VBAT2
VCC
VNEG
VREG
VTX
Input
Input
Output
Output
Output
Battery
Battery
Power
Power
Input
Output
PRELIMINARY
Description
Analog and Digital ground are connected internally to a single pin.
Output of A(TIP) power amplifier.
VBAT2 Enable. Logic Low enables operation from VBAT2. Logic High enables operation
from VBAT1. TTL compatible.
Battery (power) ground.
Output of B(RING) power amplifier.
Decoder. TTL compatible. C3 is MSB and C1 is LSB.
Relay1 Control. TTL compatible. Logic Low activates the Relay1 relay driver.
(Option) Relay2 Control. TTL compatible. Logic Low activates the Relay2 relay driver.
Detector. Logic Low indicates that the selected detector is tripped. Logic inputs C3–C1,
E1, and E0 select the detector. Open-collector with a built-in 15 kΩ pull-up resistor.
(Option) A logic High selects the off-hook detector. A logic Low selects the ground-key
detector. TTL compatible.
High-pass filter capacitor; A(TIP) side of high-pass filter capacitor.
High-pass filter capacitor; B(RING) side of high-pass filter capacitor.
Detector resistor. Threshold modification/filter point for the off-hook detector.
DC feed resistor. Connection point for the DC feed current programming network, which
also connects to the receiver summing node (RSN). VRDC is negative for normal polarity
and positive for reverse polarity.
Connection point for feedback during ringing.
Ring Signal Input. Pin for ring signal input. Square-wave shaped by external RC filter.
Requires 50% duty cycle. CMOS-compatible input.
Saturation Guard High. Pin for resistor to adjust Open Circuit voltage when operating
from VBAT1.
Saturation Guard Low. Pin for resistor to adjust the anti-saturation cut-in voltage when
operating from both VBAT1 and VBAT2.
The metallic current (AC and DC) between A(TIP) and B(RING) is equal to 1000 x the
current into this pin. The networks that program receive gain, two-wire impedance, and
feed current all connect to this node.
Ring-trip detector. Ring-trip detector threshold set and filter pin.
Ring-trip detector threshold offset (switch to VBAT1). For power conservation in any
nonringing state, this switch is open.
Common Emitter of RYOUT1/RYOUT2. Emitter output of RYOUT1 and RYOUT2.
Normally connected to relay ground.
Relay/switch driver. Open collector driver with emitter internally connected to RYE.
(Option) Relay/switch driver. Open collector driver emitter internally connected to RYE.
Battery supply and connection to substrate.
Power supply to output amplifiers. Connect to off-hook battery through a diode.
Positive analog power supply.
Negative analog power supply. This pin is the return for the intern VEE regulator.
Regulated Voltage. Provides negative power supply for power amplifiers, connection
point for inductor, filter capacitor, and chopper stabilization.
Transmit Audio. This output is 0.5066 times the A(TIP) and B(RING) metallic voltage.
VTX also sources the two-wire input impedance programming network.
SLIC Products
5
5 Page 
PRELIMINARY
Table 2. User-Programmable Components
ZT = 500(Z2WIN – 2RF)
ZT is connected between the VTX and RSN pins. The fuse resistors are
RF, and Z2WIN is the desired 2-wire AC input impedance. When
computing ZT, the internal current amplifier pole and any external stray
capacitance between VTX and RSN must be taken into account.
ZRX = ---Z----L---- • --------------1---0---0---0----•----Z----T---------------
G42L ZT + 500(ZL + 2RF)
ZRX is connected from VRX to RSN. ZT is defined above, and G42L is the
desired receive gain.
RDC1 + RDC2 = --2---5---0---0---
ILOOP
RDC1, RDC2, and CDC form the network connected to the RDC pin.
ILOOP is the desired loop current in the constant-current region.
RDCR1 + RDCR2 = ------3---0---0---0------
Iringlim
CDC = 19 ms • R-----D---C----1----+-----R----D----C---2-
RDC1RDC2
CDCR = R-----D----C---R---1----+-----R----D----C----R---2- • 150 µs
RDCR1RDCR2
RD = RLTH • 12.67 for high battery state
Loop-Threshold Detect Equations
RLTH = ---R-----D---- for high battery
12.67
RDCR1, RDCR2, and CDCR form the network connected to the RDCR pin.
See Applications Circuit for these components.
CDCR sets the ringing time constant, which can be between 15 µs and
150 µs.
RD is the resistor connected from the RD pin to GND and RLTH is the
loop-resistance threshold between on-hook and off-hook detection. RD
should be greater than 56 kΩ to guarantee detection will occur in the
Standby state. Choose the value of RD for high battery state; then use
the equation for RLTH to find where the threshold is for low battery.
This is the same equation as for RD in the preceding equation, except
solved for RLTH.
RLTH = ---R-----D---- for low battery
11.37
For low battery, the detect threshold is slightly higher, which will avoid
oscillating between states.
RLTH = --V-----B---A----T---1----–---1---0-- • RD – 400 – 2RF
915
RLTH standby < RLTH active VBAT1 < RLTH active VBAT2, which will
guarantee no unstable states under all operating conditions. This
equation will show at what resistance the standby threshold will be; it is
actually a current threshold rather than a resistance threshold, which is
shown by the Vbat dependency.
SLIC Products
11
11 Page | ||
| Páginas | Total 17 Páginas | |
| PDF Descargar | [ Datasheet AM79R70JC.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AM79R70JC | Ringing Subscriber Line Interface Circuit | Advanced Micro Devices |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |