參數(shù)資料
型號(hào)： HC55142IM
廠(chǎng)商： HARRIS SEMICONDUCTOR
元件分類(lèi)： 模擬傳輸電路
英文描述： Low Power Universal SLIC Family
中文描述： TELECOM-SLIC, PQCC28
文件頁(yè)數(shù)： 24/35頁(yè)
文件大?。?/td> 382K
代理商： HC55142IM
4-24
Interface to Dual and Single Supply
CODECs
Great care has been taken to minimize the number of external
components required with the UniSLIC14 family while still
providing the maximum flexibility. Figures 24A, 24B) shows
the connection of the UniSLIC14 to both a dual supply
CODEC/Filter and a single supply DSP CODEC/Filter.
To eliminate the DC blocking capacitors between the SLIC
and the CODEC/Filter when using a dual supply
CODEC/Filter, both the receive and transmit leads of the
SLIC are referenced to ground. This leads to a very simple
SLIC to CODEC/Filter interface, as shown in Figure 24A.
When using a single supply DSP CODEC/Filter the output
and input of the CODEC/Filter are no longer referenced to
ground. To achieve maximum voltage swing with a single
supply, both the output and input of the CODEC/Filter are
referenced to its own V
CC
/2 reference. Thus, DC blocking
capacitors are once again required. By using the PTG pin of
the UniSLIC14 and the externally supplied V
CC
/2 reference
of the CODEC/Filter, one of the DC blocking capacitors can
be eliminated (Figure 24B).
Power Management
The UniSLIC14 family provides two distinct power
management capabilities:
Power Sharing and Battery Selection
Power Sharing
Power sharing is a method of redistributing the power away
from the SLIC in short loop applications. The total system
power is the same, but the die temperature of the SLIC is
much lower. Power sharing becomes important if the
application has a single battery supply (-48V on hook
requirements for faxes and modems) and the possibility of
high loop currents (reference Figure 25). This technique
would prevent the SLIC from getting too hot and thermally
shutting down on short loops.
The power dissipation in the SLIC is the sum of the smaller
quiescent supply power and the much larger power that
results from the loop current. The power that results from the
loop current is the loop current times the voltage across the
SLIC. The power sharing resistor (R
PS
) reduces the voltage
across the SLIC, and thereby the on-chip power dissipation.
The voltage across the SLIC is reduced by the voltage drop
across R
PS
. This occurs because R
PS
is in series with the
loop current and the negative supply.
A mathematical verification follows:
Given: V
BH
= V
BL
= -48V, Loop current = 30mA, R
L
(load
across tip and ring) = 600
, Quiescent battery power =
(48V) (0.8mA) = 38.4mW, Quiescent VCC power = (5V)
(2.7mA) = 13.5mW, Power sharing resistor = 600
.
1. Without power sharing, the on-chip power dissipation
would be 952mW (Equation 41).
2. With power sharing, the on-chip power dissipation is
412mW (Equation 42). A power redistribution of 540mW.
On-chip power dissipation without power sharing resistor.
On-chip power dissipation with 600
power sharing resistor.
(
)
30mA
(
)
38.4mW
+
+
=
)
2
–
R
PS
The design trade-off in using the power sharing resistor is
loop length vs on-chip power dissipation.
FIGURE 24A.
FIGURE 24B.
FIGURE 24. INTERFACE TO DUAL AND SINGLE SUPPLY
CODECs
V
TX
+
-
A = 1
V
RX
UniSLIC14
V
OUT
DUAL SUPPLY
CODEC/FILTER
+
-
5V
GND
-5V
V
TX
500K
PTG
+
-
A = 1
500K
V
RX
UniSLIC14
SINGLE SUPPLY
DSP
CODEC/FILTER
5V
GND
V
IN
V
OUT
V
REF
PD
V
BH
(
)
30mA
(
)
38.4mW
13.5mW
RL
(
)
30mA
(
)
2
–
+
+
=
(EQ. 41)
PD
952mW
=
PD
V
BH
(
13.5mW
)
2
(EQ. 42)
R
L
)
30mA
(
(
)
30mA
(
–
PD
412mW
=
FIGURE 25. POWER SHARING (SINGLE SUPPLY SYSTEMS)
V
TX
V
RX
UniSLIC14
TIP
RING
V
BL
V
BH
-48V
-48V
ON SHORT LOOPS, THE
MAJORITY OF CURRENT
FLOWS OUT THE V
BL
PIN
R
PS
HC55120, HC55121, HC55130, HC55131, HC55140, HC55141, HC55142, HC55143, HC55150, HC55151
相關(guān)PDF資料
PDF描述
HC55143 Low Power Universal SLIC Family
HC55143IM Low Power Universal SLIC Family
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HC55150CB Low Power Universal SLIC Family
HC55150CM Low Power Universal SLIC Family
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HC55142IM96 制造商:INTERSIL 制造商全稱(chēng):Intersil Corporation 功能描述:Low Power Universal SLIC Family
HC55142IMZ 功能描述:電信線(xiàn)路管理 IC LW PWR SLIC POLV/MTRING 53DB RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類(lèi)型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
HC55142IMZ96 功能描述:電信線(xiàn)路管理 IC HC55142IM IN TAPE RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類(lèi)型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
HC55143 制造商:INTERSIL 制造商全稱(chēng):Intersil Corporation 功能描述:Low Power Universal SLIC Family
HC55143IM 功能描述:IC SLIC UNIVERSAL LP 32-PLCC RoHS:否 類(lèi)別:集成電路 (IC) >> 接口 - 電信 系列:UniSLIC14 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS 產(chǎn)品變化通告:Product Discontinuation 06/Feb/2012 標(biāo)準(zhǔn)包裝:750 系列:*
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