LE87281NQCT [MICROCHIP]
Line Driver, 2 Func, 2 Driver;
| 型号： | LE87281NQCT |
| 厂家： | 
MICROCHIP |
| 描述： | Line Driver, 2 Func, 2 Driver 驱动 接口集成电路 驱动器 |
| 文件： | 总10页 (文件大小：626K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Le87281
G.Fast
Single Channel Line Driver
Preliminary Data Sheet
Document ID# 147990
Version 5
December 2017
FEATURES
•
•
•
Supports high frequency G.Fast transmission
ORDERING INFORMATION
Supports VDSL2 and ADSL2+ operation
Very low power dissipation
Le87281NQC
Le87281NQCT
16-pin QFN Green Package
16-pin QFN Green Package
Tray
Tape and Reel
–
Class AB operation
•
•
•
5 programmable states
The green package meets RoHS 2 Directive 2011/65/EU of the
No external gain resistors required
Small footprint package
European Council to minimize the environmental impact of electrical
equipment.
–
16-pin (4 mm x 4 mm) QFN
•
RoHS compliant
BLOCK DIAGRAM
APPLICATIONS
•
•
•
G.Fast Line Driver
S
VS
VDSL2 Line Driver
Mode
Control
EN
ADSL2+ CPE Line Driver
GND
VS
DESCRIPTION
VINA
+
–
VOUTA
A
The Le87281 is a single channel differential amplifier
designed to drive G.Fast transmission signals as well as
VDSL2 and ADSL2+ signals with very low power
dissipation. The Le87281 contains a pair of wideband
amplifiers designed with Microsemi’s HV15 Bipolar SOI
process for low power consumption.
VS
GND
The line driver gain is fixed internally. The amplifiers are
powered from a single supply.
VS
The device can be programmed to one-of-three preset
Bias levels or to impedance controlled Disable or
Standby states. The control pins respond to input levels
that can be generated with a standard tri-state GPIO.
GND
–
+
VOUTB
B
VINB
GND
The Le87281 is available in a 16-pin (4 mm x 4 mm)
QFN package with exposed pad for enhanced thermal
conductivity.
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
TABLE OF CONTENTS
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Connection Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Package Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Device Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
State Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Line Driver Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
16-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
CONNECTION DIAGRAM
Top View
16 15 14 13
1
2
3
4
12
11
10
9
NC
IREF
VINA
VINB
GND
VS
16-pin QFN
GND
NC
EXPOSED PAD
5
6
7
8
Note:
1. Pin 1 is marked for orientation.
2. The Le87281 device incorporates an exposed die pad on the underside of its package. The pad acts as a heat sink and must be connected
to a copper plane through thermal vias, for proper heat dissipation. It is electrically isolated and maybe connected to GND.
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
PIN DESCRIPTIONS
Pin #
Pin Name
Type
Input
Description
Device internal reference current. Connect a resistor (RREF) to GND.
1
IREF
VINA
VINB
GND
NC
2
Input
Non-inverting input of amplifier A
Non-inverting input of amplifier B
Reference ground
3
Input
4
Ground
5
No internal connection
Amplifier B output
6
VOUTB
EN
Output
Input
7
Enable transmission
8
NC
No internal connection
9
NC
10
11
12
13
14
15
16
GND
VS
Ground
Power
Reference ground
Power Supply, +12 V
NC
NC
No internal connection
NC
VOUTA
S
Output
Input
Amplifier A output
State control
Exposed pad
Electrically isolated thermal conduction pad, can be grounded
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
ABSOLUTE MAXIMUM RATINGS
Stresses above the values listed under Absolute Maximum Ratings can cause permanent device failure.
Functionality at or above these limits is not implied. Exposure to absolute maximum ratings for extended periods can
affect device reliability.
-65 TA +150 °C
-40 Tj +150 °C
Storage Temperature
Operating Junction Temperature (1)
VS with respect to GND
-0.3 V to +16 V
-0.3 V to 4 V
100 mA
Control inputs with respect to GND
Continuous Driver Output Current
Maximum device power dissipation, continuous (2) - TA = 85°C, PD
1.0 W
Junction to ambient thermal resistance (2,3), JA
52.0 °C/W
26.0 °C/W
14.6 °C/W
3.1 °C/W
Junction to board thermal resistance (2), JB
Junction to case bottom (exposed pad) thermal resistance, JC (BOTTOM)
Junction-to-top characterization parameter (2), JT
ESD Immunity (Human Body Model)
ESD Immunity (Charge Device Model)
JESD22 Class 2 compliant
JESD22 Class IV compliant
Notes:
1. Continuous operation above 145°C junction temperature may degrade device reliability.
2. See Thermal Resistance.
3. No air flow.
Thermal Resistance
The thermal performance of a thermally enhanced package is assured through optimized printed circuit board layout.
Specified performance requires that the exposed thermal pad be soldered to an equally sized exposed copper
surface, which, in turn, conducts heat through multiple vias to larger internal copper planes.
Package Assembly
The green package devices are assembled with enhanced, environmental compatible lead-free, halogen-free, and
antimony-free materials. The leads possess a matte-tin plating which is compatible with conventional board
assembly processes or newer lead-free board assembly processes.
Refer to IPC/JEDEC J-Std-020 Table 4 for recommended peak soldering temperature and Table 5-2 for the
recommended solder reflow temperature profile.
OPERATING RANGES
Microsemi guarantees the performance of this device over the industrial (-40°C to 85°C) temperature range by
conducting electrical characterization over each range and by conducting a production test with single insertion
coupled with periodic sampling. These characterization and test procedures comply with the Telcordia GR-357-
CORE Generic Requirements for Assuring the Reliability of Components Used in Telecommunications Equipment.
TA
Ambient temperature
Power Supply
-40°C to +85°C
VS with respect to GND
+11.40V to +15.75V
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
DEVICE SPECIFICATIONS
Typical Conditions: As shown in the basic test circuit (Figure 1) with VS = +12 V, R
= 75 k, and T = 25°C.
REF
A
Min/Max Parameters: T = -40 to +85°C.
A
Table 1. Electrical Specifications
Parameter
Symbol
Description
Condition
Min
Typ
Max
Unit
Notes
Supply Current Characteristics
Transmission, PLINE = 4 dBm,
Full Bias
470
600
mW
PVS
Supply Power
Receive period, Disable state
175
1
250
1.5
mW
mA
PIS
Control Input (S, EN) Specifications
Supply Current
Standby State
VIH
VIM
VIL
Input High Voltage
2.0
3.3
1.5
3.6
0.8
V
V
Input Middle Voltage
Input Low Voltage
Enable Time
-0.3
0
V
500
500
ns
ns
Disable Time
Disable state
Amplifier Characteristics
Differential Gain
VOUT/VIN
18.3
-1.5
18.8
10
19.1
1
dB
dB
V
Gain Flatness
2 106 MHz
1
1
VO
IO
Output Voltage
Output Current
Input Impedance
Output Impedance
150
13
mA
k
ZI
Differential
15
60
18
15
ZO
Disable state
Amplifier Dynamic Characteristics
Noise
Input Referred Noise
2 106 MHz
9
1
nV/ Hz
°C
Thermal Shutdown
Temperature
TSD
170
Notes:
1. Not tested in production. Guaranteed by characterization and design.
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
RREF
75K, 1%
Le87281
IREF
VINA
+
–
VOUTA
A
RLOAD
170
–
+
VOUTB
B
VINB
Figure 1. Basic Test Circuit
STATE CONTROL
S and EN pins are used as combinatorial logic inputs to control the line driver operating states. Table 2 shows the
programmable states.
S and EN are tri-state inputs that accept three operating levels. These pins have internal resistors tied to +1.5 V
which force a middle logic input level when the control to these pins is tri-stated.
Table 2. Control Matrix
S
EN
State
Application
X
X
0
Disable
Standby
Open
0
1
1
1
Enable Low Bias
Enable Medium Bias
Enable Full Bias
ADSL2+
VDSL2
G.Fast
Open
1
Disable State: Amplifier output = VS/2. The Disable state should be used during the receive period. The device
presents a controlled low impedance to the line during this state.
Standby State: Amplifier bias current removed. This is the lowest power state. Amplifier output is high impedance.
Gain-setting feedback resistors are still connected across amplifier output pins, creating 1300 ohm differential
impedance at pins.
Bias States: Line Driver is active for transmission. States are different only in the amount of bias current to the
amplifiers, and therefore power consumption. There is a trade-off between bias current and bandwidth.
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
APPLICATIONS
The Le87281 integrates a set of high-power line driver amplifiers that can be connected for half-duplex differential
line transmissions. The amplifiers are designed to be used with signals up to 106 MHz with low signal distortion.
Figure 2 shows an application circuit with amplifiers A and B in transmission.
Le87281
VINA
+
–
50
VOUTA
A
VLINEA
RLINE
100
1:1 VLINEB
50
–
+
VOUTB
IREF
B
VINB
75K
Figure 2. Typical Application Circuit
Input Considerations
The driving source impedance should be less than 100 nH to avoid any ringing or oscillation.
Output Driving Considerations
The internal metallization is designed to carry up to about 100 mA of steady DC current and there is no current limit
mechanism. The device does feature integrated thermal shutdown protection however with hysteresis. Driving lines
with no series resistor is not recommended.
Power Supplies and Component Placement
The power supplies should be well bypassed close to the Le87281 device. A 2.2 µF tantalum capacitor and a 0.1 µF
ceramic capacitor for the VS supply is recommended.
Line Driver Protection
High voltage transients such as lightning can appear on the telephone lines. Transient protection devices should be
used to absorb the transient energy and clamp the transient voltages. The series output termination resistors limit
the current going into the line driver and internal clamps. The protection scheme depends on the type of data
transformer used and the line protection components used in the front of the data transformer.
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Microsemi Corporation Confidential and Proprietary
Le87281
Preliminary Data Sheet
PHYSICAL DIMENSIONS
16-Pin QFN
Note:
Packages may have mold tooling markings on the surface. These markings have no impact on the form, fit or function of the de-
vice. Markings will vary with the mold tool used in manufacturing.
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Microsemi Corporation Confidential and Proprietary
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and alternative energy markets. Products include mixed-signal ICs, SoCs, and ASICs;
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