参数资料
| 型号： | ISL1532IRZ |
| 厂商： | Intersil |
| 文件页数： | 6/19页 |
| 文件大小： | 0K |
| 描述： | IC LINE DRIVER DUAL 24-QFN |
| 标准包装： | 90 |
| 类型： | 驱动器 |
| 驱动器/接收器数： | 2/0 |
| 规程： | DSL |
| 电源电压： | 5 V ~ 15 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-VFQFN 裸露焊盘 |
| 供应商设备封装： | 24-QFN（5x4） |
| 包装： | 散装 |
| 其它名称： | Q3116466 |
14
FN6173.3
December 4, 2006
output swing. There is a trade off, however, with the selection
of transformer ratio. As the ratio is increased, the receive
signal available to the receivers is reduced.
Once the user has selected the transformer ratio, the
dissipation in the output stages can be selected with the
following equation:
where:
VS is the supply voltage (VS+ to VS-)
VO is the average output voltage per channel
IO is the average output current per channel
The overall power dissipation (PDISS) is obtained by
summing PDquiescent and PDtransistor.
Estimating Line Driver Power Dissipation in
ADSL2+ CO Applications
Figure 46 shows a typical ADSL CO line driver
implementation. The average line power requirement for the
ADSL2+ CO application is 20dBM (100mW) into a 100
Ω line
which translated to 3.16VRMS line voltage. The ADSL2+
DMT peak to average ratio (crest factor) of 5.3 implies peak
voltage of 16.7V into the line. Using a differential drive
configuration and transformer coupling with standard back
termination, a transformer ratio of 1:1 is selected. With 1:1
transformer ratio, the impedance across the driver side of
the transformer is 100
Ω, the average voltage is 3.16VRMA
and the average current is 31.6mA. The power dissipated in
the ISL1532 is a combination of the quiescent power and the
output stage power when driving the line:
In the full power mode and with 1.5k RADJ resistor, the
ISL1532 consumes typically 2.7mA quiescent current per
amplifier and still able to maintain very low distortion. The
distortion results are shown in typical performance section of
the data sheet. When driving a load, a large portion (about
50%) of the quiescent current becomes output load current.
The total power dissipation per channel is:
where:
The total power dissipation for dual channel is:
PDtotal
= 2 x PD
= 1247mW
The
θJA requirement needs to be calculated. This is done
using the equation:
where:
TJUNCT is the maximum die temperature (+150°C)
TAMB is the maximum ambient temperature (+85°C)
PDISS is the dissipation calculated above
θ
JA is the junction to ambient thermal resistance for the
package when mounted on the PCB
PCB Layout Considerations for QFN and HTSSOP
Packages
The ISL1532 die is packaged in two thermally-efficient
packages: a 24 Ld QFN (leadless plastic) and 20 Ld
HTSSOP packages. Both have the thermal pads underneath
the package and can use PCB surface metal vias areas and
internal ground planes to spread heat away from the
package. The larger the PCB area, the lower the junction
temperature of the device will be. In ADSL applications,
multiple layer circuit boards with internal ground plane are
generally used. 13 mil vias are recommended to connect the
metal area under the device with the internal ground plane.
Examples of the PCB layouts for the QFN and HTSSOP
37°C/W (QFN package) and +35°C/W (HTSSOP package)
are obtained with the ISL1532 demoboard. The demoboard
is a 4-layer board built with 2 oz. copper and has a
dimension of 4 in2.
A separate application note for the QFN package and layout
recommendation is available. If using the QFN package, the
layout and manufacturing process recommendations should
be carefully reviewed.
P
Dtransistors
2I
O
V
S
2
------- - V
O
×
=
(EQ. 3)
P
D
P
quiescent
P
output-stage
+
=
P
D
V
S
I
S
(
-
×
2I
X )
V
S
(
- 2
V
OUT-RMS )
I
OUT-RMS
×
+
=
(EQ. 4)
P
D
24
2.7mA
(
250%
) 2 31.6mA
×
+
×
12
(
×
- 3.16
)
=
(EQ. 5)
P
D
623mW
=
Θ
JA
T
JUNCT - TAMB
P
DISS
---------------------------------------------
=
(EQ. 6)
Θ
JA
150 - 85
1247mW
------------------------
52
°C/W
=
(EQ. 7)
-
+
-
+
TXFR
1:1
50
RF
1.5k
Ω
100
RT
VS-
VS+
VS-
VS+
3k
2RG
TX+
TX-
From
AFE
0.22F
FIGURE 46. TYPICAL ADSL CO LINE DRIVER
IMPLEMENTATION
ISL1532
相关PDF资料 |
PDF描述 |
|---|---|
| ISL1536IRZ | IC LINE DRVR DUAL ADSL2+ 16-QFN |
| ISL1539AIRZ | IC VDSL2 LINE DVR AMP 24QFN |
| ISL1539IVEZ | IC VDSL2 LINE DVR AMP 24HTTSOP |
| ISL1557AIRZ | IC LINE DRIVER DUAL 16-QFN |
| ISL1557IUEZ | IC VDSL2 LINE DVR AMP 10HMSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL1532IRZ-T13 | 制造商:Intersil Corporation 功能描述:ADSL DRVR DUAL 24QFN EP - Tape and Reel |
| ISL1532IRZ-T7 | 功能描述:缓冲器和线路驱动器 Dual Channel Diff. DSL Line Driver RoHS:否 制造商:Intersil 输入线路数量: 输出线路数量: 极性: 电源电压-最大: 电源电压-最小: 最大工作温度:+ 85 C 安装风格: 封装 / 箱体:QFN EP 封装:Reel |
| ISL1532IVEZ | 制造商:Intersil Corporation 功能描述:OP AMP DUAL CURRENT FDBK 15V 20HTSSOP - Bulk 制造商:Rochester Electronics LLC 功能描述: |
| ISL1532IVEZ-EVAL | 制造商:Intersil Corporation 功能描述:ISL1532IVEZ-EVAL DEMO BOARD - Bulk |
| ISL1532IVEZ-T13 | 制造商:Intersil Corporation 功能描述:ADSL DRVR DUAL 20HTSSOP EP - Tape and Reel 制造商:Intersil Corporation 功能描述:Dual Channel Differential DSL Line Drive |
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