
9
Applications Diagram
FIGURE 1. TYPICAL LINE CIRCUIT APPLICATION WITH THE MONOLITHIC SLIC
Typical Component Values
C2 = 0.15F, 10V.
C3 = 0.3F, 30V.
C4 = 0.5F to 1.0F, 10%, 20V (Should be nonpolarized).
C5 = 0.5F, 20V.
C6 = C7 = 0.5F (10% Match Required) (Note 7).
C8 = 0.01F, 100V.
C9 = 0.01F, 20V, ±20%.
R1 = R2 = R3 = 100k (0.1% Match Required, 1% absolute
value) ZB = 0 for 600
Terminations (Note 7).
RB1 = RB2 = RB3 = RB4 = 150 (0.1% Match Required, 1%
absolute value).
RS1 = RS2 =1k, typically.
CS1 = CS2 = 0.1F, 200V typically, depending on VRING
and line length.
Z1 = 150V to 200V transient protection.
PTC used as ring generator ballast.
NOTES:
5. Secondary protection diode bridge recommended is a 2A, 200V type.
6. To obtain the specified transhybrid loss it is necessary for the three legs of the balance network, C6-R1 and R2 and C7-ZB-R3, to match in
impedance to within 0.3%. Thus, if C6 and C7 are 1F each, a 20% match is adequate. It should be noted that the transmit output to C6 sees
a -22V step when the loop is closed. Too large a value for C6 may produce an excessively long transient at the op amp output to the PCM
Filter/CODEC.
A 0.5
F and 100k gives a time constant of 50ms. The uncommitted op amp output is internally clamped to stay within ±6.6V and is current
limited.
7. All grounds (AG, BG, and DG) must be applied before VB+ or VB-. Failure to do so may result in premature failure of the part. If a user wishes
to run separate grounds off a line card, the AG must be applied first.
8. Application shows Ring Injected Ringing, Balanced or Tip injected configuration may be used.
9. Pin numbers given for SOIC package.
RB4
K1B
K1A
RING
RING FEED
RING FEED SENSE
TIP
VB -
SLIC
HC-5504B
RS1
RB2
RB1
PTC
Z1
-48V
150VPEAK (MAX)
RING GENERATOR
RING
RB3
RS2
CS2
SUBSCRIBER
LOOP
-48V
SYSTEM CONTROLLER
K1
8
1
9
10
3
2
1
TIP FEED
TIP
RD
OP AMP
RX
TX
+IN
-IN
OUT
C2
C3
C4
NEG.
BATT.
GND.
DIG.
GND.
ANA.
GND.
VB+
POWER
DENIAL
SWITCH
HOOK
DETECT
GROUND
KEY
DETECT
RING
SYNC
RING
CMD
15
13
14
7
16
11
12
6
23
C9
4
VB +
C8
C4
C3
C2
+
21
24
20
19
18
17
5
22
C6
R1
R2
C7
C5
R3
BALANCE NETWORK
PCM
FILTER/
CODEC
SWITCHING
NETWORK
ZB
5V TO
12V
PRIMARY
PROTECTION
CS1
HC-5504B