HC5526 Datasheet, PDF (16/18 Pages) Intersil Corporation – ITU CO/PABX SLIC with Low Power Standby

HC5526
Pin Descriptions
PLCC PDIP SYMBOL
DESCRIPTION
1
RING_SENSE Internally connected to output of RING power amplifier.
2
7
BGND Battery Ground - To be connected to zero potential. All loop current and longitudinal current flow from this ground.
Internally separate from AGND but it is recommended that it is connected to the same potential as AGND.
4
8
V_CC
5V power supply.
5
9
RINGRLY Ring relay driver output.
6
10
7
11
8
12
V_BAT
R_SG
E1
Battery supply voltage, -24V to -56V.
Saturation guard programming resistor pin.
TTL compatible logic input. The logic state of E1 in conjunction with the logic state of C1 determines which detector
is gated to the DET output.
9
13
E0
TTL compatible logic input. Enables the DET output when set to logic level zero and disables DET output when set
to a logic level one.
11
14
12
15
DET
C2
Detector output. TTL compatible logic output. A zero logic level indicates that the selected detector was triggered
(see Truth Table for selection of Ground Key detector, Loop Current detector or the Ring Trip detector). The DET
output is an open collector with an internal pull-up of approximately 15kΩ to V_CC.
TTL compatible logic input. The logic states of C1 and C2 determine the operating states (Open Circuit, Active,
Ringing or Standby) of the SLIC.
13
16
C1
TTL compatible logic input. The logic states of C1 and C2 determine the operating states (Open Circuit, Active,
Ringing or Standby) of the SLIC.
14
17
15
18
R_DC
AGND
DC feed current programming resistor pin. Constant current feed is programmed by resistors R_DC1 and R_DC2
connected in series from this pin to the receive summing node (RSN). The resistor junction point is decoupled to
AGND to isolate the AC signal components.
Analog ground.
16
19
RSN
Receive Summing Node. The AC and DC current flowing into this pin establishes the metallic loop current that
flows between tip and ring. The magnitude of the metallic loop current is 1000 times greater than the current into
the RSN pin. The constant current programming resistors and the networks for program receive gain and 2-wire
impedance all connect to this pin.
18
20
19
21
V_EE
-5V power supply.
V_TX
Transmit audio output. This output is equivalent to the TIP to RING metallic voltage. The network for programming
the 2-wire input impedance connects between this pin and RSN.
20
22
21
1
22
2
23
3
HPR
HPT
RD
DT
RING side of AC/DC separation capacitor C_HP. C_HP is required to properly separate the ring AC current from the
DC loop current. The other end of C_HP is connected to HPT.
TIP side of AC/DC separation capacitor C_HP. C_HP is required to properly separate the tip AC current from the DC
loop current. The other end of C_HP is connected to HPR.
Loop current programming resistor. Resistor R_D sets the trigger level for the loop current detect circuit. A filter
capacitor C_D is also connected between this pin and V_EE.
Input to ring trip comparator. Ring trip detection is accomplished by connecting an external network to a
comparator in the SLIC with inputs DT and DR.
25
4
DR
Input to ring trip comparator. Ring trip detection is accomplished by connecting an external network to a
comparator in the SLIC with inputs DT and DR.
26
TIP_SENSE Internally connected to output of tip power amplifier.
27
5
TIPX Output of tip power amplifier.
28
6
RINGX Output of ring power amplifier.
3, 10,
17, 24
N/C
No internal connection.
72