DATASHEET

EL1508
®
Data Sheet
March 26, 2007
FN7014.5
Differential DSL Line Driver
Features
The EL1508 is designed for driving full rate ADSL signals in
both CO and CPE applications at very low power dissipation.
The high drive capability of 450mA makes this driver ideal
for both CAP and DMT designs. It contains two wideband,
high-voltage, current mode feedback amplifiers with a
number of power dissipation reduction features.
• 450mA output drive capability
• 43.6VP-P differential output drive into 100Ω
• 2nd/3rd harmonics of -85dBc/-75dBc
• MTPR of -70dB
• Operates down to 3mA per amplifier supply current
These drivers achieve an MTPR distortion measurement of
better than 70dB, while consuming typically 6mA of total
supply current. This supply current can be set using a
resistor on the IADJ pin. Two other pins (C0 and C1) can
also be used to adjust supply current to one of four pre-set
modes (full-IS, 2/3-IS, 1/3-IS, and full power-down). The
EL1508 operates on ±5V to ±12V supplies and retains its
bandwidth and linearity over the complete supply range.
• Power control features
• Pin-compatible with EL1503
• Pb-free plus anneal available (RoHS compliant)
Applications
• ADSL line driver
• HDSL line driver
The device is supplied in a thermally-enhanced 20 Ld SOIC
(0.300”), a thermally-enhanced 16 Ld SOIC (0.150”), and the
small footprint (4x5mm) 24 Ld QFN packages. The EL1508
is specified for operation over the full -40°C to +85°C
temperature range.
• Video distribution amplifier
• Video twisted-pair line driver
Pinouts
18 VS+
VS- 3
- +
GND* 4
GND* 5
VS- 3
17 GND*
GND* 4
16 GND*
GND* 5
GND* 6
15 GND*
VIN+A 6
GND* 7
14 GND*
C1 7
VIN+A 8
13 VIN+B
C0 8
14 VS+
13 GND*
12 GND*
11 VIN+B
POWER
CONTROL
LOGIC
20 VOUTB
21 VIN-B
22 NC
15 VOUTB
23 VIN-A
16 VIN-B
VOUTA 2
B
+ -
A
24 VOUTA
19 VOUTB
VOUTA 2
VIN-A 1
- +
20 VIN-B
VIN-A 1
EL1508
(24 LD QFN)
TOP VIEW
EL1508
[16 LD SOIC (0.150”)]
TOP VIEW
+ -
EL1508
[20 LD SOIC (0.300”)]
TOP VIEW
NC 1
19 NC
NC 2
18 NC
VS- 3
17 VS+
THERMAL
PAD
NC 4
16 NC
NC 5
15 NC
NC 6
14 NC
10 IADJ
9 NC
1
VIN+B 12
*GND PINS ARE HEAT SPREADERS
IADJ 11
11 NC
13 GND
C0 10
12 IADJ
C1 9
C0 10
POWER
CONTROL
LOGIC
VIN+A 8
GND 7
C1 9
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2001-2005, 2007. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
EL1508
Ordering Information
PART NUMBER
PART MARKING
TAPE & REEL
PACKAGE
PKG. DWG. #
EL1508CS
EL1508CS
-
16 Ld SOIC (0.150”)
MDP0027
EL1508CS-T7
EL1508CS
7”
16 Ld SOIC (0.150”)
MDP0027
EL1508CS-T13
EL1508CS
13”
16 Ld SOIC (0.150”)
MDP0027
EL1508CSZ (See Note)
EL1508CSZ
-
16 Ld SOIC (0.150”) (Pb-Free)
MDP0027
EL1508CSZ-T7 (See Note)
EL1508CSZ
7”
16 Ld SOIC (0.150”) (Pb-Free)
MDP0027
EL1508CSZ-T13 (See Note)
EL1508CSZ
13”
16 Ld SOIC (0.150”) (Pb-Free)
MDP0027
EL1508CM
EL1508CM
-
20 Ld SOIC (0.300”)
MDP0027
EL1508CM-T13
EL1508CM
13”
20 Ld SOIC (0.300”)
MDP0027
EL1508CMZ (See Note)
EL1508CMZ
-
20 Ld SOIC (0.300”) (Pb-Free)
MDP0027
EL1508CMZ-T13 (See Note)
EL1508CMZ
13”
20 Ld SOIC (0.300”) (Pb-Free)
MDP0027
EL1508CL
1508CL
-
24 Ld QFN
MDP0046
EL1508CL-T7
1508CL
7”
24 Ld QFN
MDP0046
EL1508CL-T13
1508CL
13”
24 Ld QFN
MDP0046
EL1508CLZ (See Note)
1508CLZ
-
24 Ld QFN (Pb-Free)
MDP0046
EL1508CLZ-T7 (See Note)
1508CLZ
7”
24 Ld QFN (Pb-Free)
MDP0046
EL1508CLZ-T13 (See Note)
1508CLZ
13”
24 Ld QFN (Pb-Free)
MDP0046
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
2
FN7014.5
March 26, 2007
EL1508
Absolute Maximum Ratings (TA = 25°C)
VS+ to VS- Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . -0.3V to 28V
VS+ Voltage to Ground . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 28V
VS- Voltage to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . -28V to 0.3V
Driver VIN+ Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VS- to VS+
C0, C1 Voltage to GND . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V
IADJ Voltage to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 4V
Current into any Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8mA
Output Current from Driver (Static) . . . . . . . . . . . . . . . . . . . . 100mA
Operating Temperature Range . . . . . . . . . . . . . . . . .-40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . . . . . . .-60°C to +150°C
Operating Junction Temperature . . . . . . . . . . . . . . .-40°C to +150°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at
the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
PARAMETER
VS = ±12V, RF = 2.2kΩ, RL= 65Ω, IADJL = C0 = C1 = 0V, TA = 25°C. Amplifiers tested separately.
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
SUPPLY CHARACTERISTICS
IS+ (Full IS)
Positive Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 0V
10
14.5
18
mA
IS- (Full IS)
Negative Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 0V
-9.5
-13.5
-17.5
mA
IS+ (2/3 IS)
Positive Supply Current per Amplifier
All outputs at 0V, C0 = 5V, C1 = 0V
7
10
12.5
mA
IS- (2/3 IS)
Negative Supply Current per Amplifier
All outputs at 0V, C0 = 5V, C1 = 0V
-6
-9
-12
mA
IS+ (1/3 IS)
Positive Supply Current per Amplifier
All outputs at 0V, C0 = 0V, C1 = 5V
3.75
5.25
7
mA
IS- (1/3 IS)
Negative Supply Current per Amplifier
All outputs at 0V, C0 = 0V, C1 = 5V
-2.75
-4.25
-6
mA
IS+ (6.8k)
Positive Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 0V,
RADJ = 6.8k
3
3.75
4.5
mA
IS- (6.8k)
Negative Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 0V,
RADJ = 6.8k
-3.75
-2.9
-2.25
mA
IS+ (Power-down)
Positive Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 5V
0.75
1.2
2
mA
IS- (Power-down)
Negative Supply Current per Amplifier
All outputs at 0V, C0 = C1 = 5V
0
-0.25
-2
mA
IGND
GND Supply Current per Amplifier
All outputs at 0V
1
mA
INPUT CHARACTERISTICS
VOS
Input Offset Voltage
-10
1
10
mV
ΔVOS
VOS Mismatch
-5
0
5
mV
IB+
Non-Inverting Input Bias Current
-15
15
µA
IB-
Inverting Input Bias Current
-50
50
µA
ΔIB-
IB- Mismatch
-25
0
25
µA
ROL
Transimpedance
1.1
2.9
5
MΩ
eN
Input Noise Voltage
3.5
nV/√ Hz
iN
-Input Noise Current
13
pA/√ Hz
VIH
Input High Voltage
C0 and C1 inputs
VIL
Input Low Voltage
C0 and C1 inputs
IIH1
Input High Current for C1
C1 = 5V
1
IIH0
Input High Current for C0
C0 = 5V
0.5
IIL
Input Low Current for C0 or C1
C0 = 0V, C1 = 0V
-1
3
2.25
V
0.8
V
2
6
µA
1
3
µA
1
µA
FN7014.5
March 26, 2007
EL1508
Electrical Specifications
PARAMETER
VS = ±12V, RF = 2.2kΩ, RL= 65Ω, IADJL = C0 = C1 = 0V, TA = 25°C. Amplifiers tested separately. (Continued)
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
RL = 100Ω
±10.6
±10.8
±11.5
V
RL = 25Ω
±9.8
±10.2
±10.6
V
OUTPUT CHARACTERISTICS
VOUT
Loaded Output Swing
IOL
Linear Output Current
AV = 5, RL = 10Ω, f = 100kHz,
THD = -60dBc
450
mA
IOUT
Output Current
VOUT = 1V, RL = 1Ω
1
A
DYNAMIC PERFORMANCE
BW
-3 dB Bandwidth
AV = +5
80
MHz
HD2
2nd Harmonic Distortion
fC = 1MHz, RL = 100Ω, VOUT = 2VP-P
-90
dBc
fC = 1MHz, RL = 25Ω, VOUT = 2VP-P
-80
dBc
fC = 1MHz, RL = 100Ω, VOUT = 2VP-P
-90
dBc
fC = 1MHz, RL = 25Ω, VOUT = 2VP-P
-75
dBc
-70
dBc
HD3
3rd Harmonic Distortion
MTPR
Multi-Tone Power Ratio
26kHz to 1.1MHz, RLINE = 100Ω,
PLINE = 20.4dBM
SR
Slewrate
VOUT from -8V to +8V measured at ±4V
4
450
600
800
V/µs
FN7014.5
March 26, 2007
EL1508
Pin Descriptions
16 Ld SOIC
(0.150")
20 Ld SOIC
(0.300")
24 Ld QFN
PIN NAME
1
1
23
VIN-A
FUNCTION
CIRCUIT
Channel A Inverting Input
CIRCUIT 1
2
2
24
VOUTA
Channel A Output
3
3
3
VS-
Negative Supply
4, 5
4, 5, 6, 7
7
GND
Ground Connection
6
8
8
VIN+A
(Reference Circuit 1)
Channel A Non-inverting Input
VS+
VS-
CIRCUIT 2
7
9
9
C1
Current Control Bit 1
VS+
6.7V
CIRCUIT 3
8
10
10
C0
Current Control Bit 2
9
11
1, 2, 4, 5, 6, 14,
15, 16, 18, 19, 22
NC
Not Connected
10
12
11
IADJ
(Reference Circuit 3)
Supply Current Control Pin
VS+
IADJ
GND
CIRCUIT 4
11
13
12
VIN+B
12, 13
14, 15, 16, 17
13
GND
Ground Connection
14
18
17
VS+
Positive Supply
15
19
20
VOUTB
16
20
21
VIN-B
5
Channel B Non-inverting Input
(Reference Circuit 2)
Channel B Output
(Reference Circuit 1)
Channel B Inverting Input
(Reference Circuit 1)
FN7014.5
March 26, 2007
EL1508
Typical Performance Curves
24
RF=2kΩ
RF=1.5kΩ
16
RF=2.5kΩ
20
GAIN (dB)
GAIN (dB)
22
18
AV=10
VS=±12V
RL=100Ω
RADJ=0Ω
RF=3kΩ
18
16
AV=5
VS=±12V
RL=100Ω
RF=2.5kΩ
14
RF=4kΩ
12
RF=3.5kΩ
1M
10M
8
100K
100M
FREQUENCY (Hz)
20
RF=3kΩ
18
RF=4kΩ
14
RF=3.5kΩ
RF=3kΩ
1M
10M
8
100K
100M
FREQUENCY (Hz)
RF=4kΩ
RF=2kΩ
RF=2.5kΩ
14
100K
RF=2kΩ
RF=3kΩ
12
RF=2.5kΩ
10
10M
100M
FREQUENCY (Hz)
FIGURE 5. DIFFERENTIAL FREQUENCY RESPONSE vs RF
(FULL POWER MODE)
6
14
RF=3.5kΩ
RF=3kΩ
1M
GAIN (dB)
GAIN (dB)
16
16
100M
AV=5
VS=±12V
RL=100Ω
RF=1.5kΩ
20
18
10M
FIGURE 4. DIFFERENTIAL FREQUENCY RESPONSE
(2/3 POWER MODE)
18
AV=10
VS=±12V
RL=100Ω
RADJ=0Ω
1M
FREQUENCY (Hz)
FIGURE 3. DIFFERENTIAL FREQUENCY RESPONSE vs RF
(2/3 POWER MODE)
22
RF=2.5kΩ
10
14
100K
24
RF=2kΩ
12
RF=2.5kΩ
16
100M
AV=5
VS=±12V
RL=100Ω
RF=1.5kΩ
GAIN (dB)
GAIN (dB)
16
RF=2kΩ
10M
FIGURE 2. DIFFERENTIAL FREQUENCY RESPONSE
(1/3 POWER MODE)
18
AV=10
VS=±12V
RL=100Ω
RADJ=0Ω
1M
FREQUENCY (Hz)
FIGURE 1. DIFFERENTIAL FREQUENCY RESPONSE vs RF
(1/3 POWER MODE)
22
RF=2kΩ
10
14
100K
24
RF=3kΩ
8
100K
1M
10M
100M
FREQUENCY (Hz)
FIGURE 6. DIFFERENTIAL FREQUENCY RESPONSE
(FULL POWER MODE)
FN7014.5
March 26, 2007
EL1508
Typical Performance Curves
MAGNITUDE (dB)
22
26
VS=±12V
RFB=3kΩ
AV=5
RL=83Ω
RSET=0Ω
100pF
MAGNITUDE (dB)
26
(Continued)
68pF
18
50pF
14
22pF
10
VS=±12V
RFB=3kΩ
22 AV=5
RL=83Ω
RSET=0Ω
18
150pF
100pF
62pF
14
39pF
10
0pF
22pF
0pF
6
10K
100K
10M
1M
6
10K
100M
100K
FREQUENCY (Hz)
VS=±12V
RFB=3kΩ
AV=10
RL=100Ω
5
150pF
PEAKING (dB)
MAGNITUDE (dB)
22
FIGURE 8. EL1508CM SINGLE-ENDED CONFIGURATION
FREQUENCY RESPONSE vs CL
(1/3 POWER MODE)
6
VS=±12V
RFB=3kΩ
AV=5
RL=83Ω
RSET=0Ω
100pF
18
62pF
14
39pF
10
100M
FREQUENCY (Hz)
FIGURE 7. EL1508CM SINGLE-ENDED CONFIGURATION
FREQUENCY RESPONSE vs CL
(1/3 POWER MODE)
26
10M
1M
22pF
4
3
2
1
5pF
6
10K
100K
10M
1M
0
100M
5
6
FIGURE 9. EL1508CM SINGLE-ENDED CONFIGURATION
FREQUENCY RESPONSE vs CL
6
9
10
VS=±7.5V
RFB=3kΩ
AV=10
RL=100Ω
6
PEAKING (dB)
PEAKING (dB)
7
4
3
2
1
0
8
FIGURE 10. PEAKING vs IS+
VS=±12V
RFB=3kΩ
AV=10
RL=100Ω
5
7
TOTAL IS (mA)
FREQUENCY (Hz)
5
4
3
2
1
0
2
4
6
8
RADJ (kΩ)
FIGURE 11. PEAKING vs RADJ
7
10
0
5
7
9
11
13
15
ISUPPLY (mA)
FIGURE 12. PEAKING vs IS+
FN7014.5
March 26, 2007
EL1508
Typical Performance Curves
(Continued)
0
40
-20
GAIN (dB)
ROUT (Ω)
30
20
-40
A to B
-60
10
B to A
-80
0
10K
100K
10M
1M
-100
10K
100M
100K
FREQUENCY (Hz)
FIGURE 13. OUTPUT IMPEDANCE
DIFFERENTIAL GAIN (%), PHASE (°)
VOLTAGE NOISE (nV/√Hz),
CURRENT NOISE (pA/√Hz)
CURRENT NOISE
10
VOLTAGE NOISE
1K
100
100K
10K
1.4
1.2
1.0
0.6
0.4
DIFF GAIN
0.20
0.15
0.10
DIFF PHASE
0.05
0
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NUMBER of 150Ω RESISTOR LOADS
FIGURE 17. DIFFERENTIAL GAIN/PHASE, FO=3.58MHz
(2/3 POWER MODE)
8
DIFF PHASE
0.2
0
1.0
1.5
2.0
2.5
3.0
3.5
4.0
FIGURE 16. DIFFERENTIAL GAIN/PHASE, FO=3.58MHz
(2/3 POWER MODE)
DIFFERENTIAL GAIN (%), PHASE (°)
DIFFERENTIAL GAIN (%), PHASE (°)
0.25
DIFF GAIN
NUMBER of 150Ω RESISTOR LOADS
FIGURE 15. VOLTAGE AND CURRENT NOISE vs FREQUENCY
VS=±12V
RFB=3kΩ
AV=2
RSET=0Ω
VS=±12V
RFB=3kΩ
AV=2
RSET=0Ω
0.8
FREQUENCY (Hz)
0.30
100M
FIGURE 14. CHANNEL SEPARATION
100
1
10
10M
1M
FREQUENCY (Hz)
0.08
VS=±12V
RFB=3kΩ
AV=2
RSET=0Ω
0.07
0.06
DIFF PHASE
0.05
0.04
DIFF GAIN
0.03
0.02
0.01
0
1
2
3
4
5
NUMBER of 150Ω RESISTOR LOADS
FIGURE 18. DIFFERENTIAL GAIN/PHASE, FO=3.58MHz
(FULL POWER MODE)
FN7014.5
March 26, 2007
EL1508
0
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
-10
-30
HD3
-50
HD2
-70
-90
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
Typical Performance Curves - 24 Ld QFN Package
0
1
2
3
4
5
6
7
8
-20
-40
HD3
-60
HD2
-80
-100
9
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
0
5
VOUTP-P (V)
-30
HARMONIC DISTORTION (dB)
-20
HD (dB)
25
20
25
20
25
0
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
-10
HD3
-40
-50
-60
HD2
-70
-80
0
1
2
3
4
5
6
7
8
-20
HD3
-40
-60
-80
HD2
-100
9
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
0
5
VOUTp-p (V)
10
15
VOUTP-P (V)
FIGURE 21. HARMONIC DISTORTION TEST
(2/3 POWER MODE)
FIGURE 22. HARMONIC DISTORTION TEST
(2/3 POWER MODE)
0
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
-10
-20
-30
HARMONIC DISTORTION (dB)
0
HARMONIC DISTORTION (dB)
20
FIGURE 20. HARMONIC DISTORTION TEST
(1/3 POWER MODE)
0
HD3
-40
-50
-60
-70
-80
HD2
-90
-100
15
VOUTP-P (V)
FIGURE 19. HARMONIC DISTORTION TEST
(1/3 POWER MODE)
-90
10
0
1
2
3
4
5
6
7
VOUTp-p (V)
FIGURE 23. HARMONIC DISTORTION TEST
(FULL POWER MODE)
9
8
9
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
-20
HD3
-40
-60
-80
HD2
-100
0
5
10
15
VOUTP-P (V)
FIGURE 24. HARMONIC DISTORTION TEST
(FULL POWER MODE)
FN7014.5
March 26, 2007
EL1508
Typical Performance Curves - 20 Ld SOIC (0.300") Package
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
-20
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
0
-40
HD2
-60
HD3
-80
-30
-50
1
2
3
4
5
6
7
8
HD 2
-70
HD 3
-90
0
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
-10
9
0
5
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
-30
-50
HD2
-70
HD3
-90
0
1
3
2
4
5
6
7
8
-30
-50
HD 2
HD 3
0
5
-40
HD2
-80
HD3
2
3
4
5
6
7
8
VOUTP-P (V)
FIGURE 29. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (FULL POWER MODE)
10
20
25
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
-10
-30
-50
HD 2
-70
HD 3
-90
1
15
FIGURE 28. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (2/3 POWER MODE)
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
FREQ=1MHz
VS=±5V
RSET=0
RL=100Ω
GAIN=10
0
10
VOUTP-P (V)
0
-100
25
-70
-90
9
FIGURE 27. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (2/3 POWER MODE)
-60
20
FREQ=1MHz
VS=±12V
RSET=0
RL=100Ω
GAIN=10
-10
VOUTP-P (V)
-20
15
FIGURE 26. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (1/3 POWER MODE)
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
FIGURE 25. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (1/3 POWER MODE)
-10
10
VOUTP-P (V)
VOUTP-P (V)
0
5
10
15
20
25
VOUTP-P (V)
FIGURE 30. HARMONIC DISTORTION vs DIFFERENTIAL
OUTPUT VOLTAGE (FULL POWER MODE)
FN7014.5
March 26, 2007
EL1508
FREQ=1MHz
VS=±5V
RSET=6.81kΩ
RL=100Ω
GAIN=10
-10
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
Typical Performance Curves
-30
HD 3
-50
HD 2
-70
0
1
2
3
5
4
7
6
-30
-70
HD2
0
1
2
VOUTP-P (V)
HARMONIC DISTORTION (dB)
HARMONIC DISTORTION (dB)
HD 2
-60
HD 3
0
5
7
8
9
0
-40
-80
6
5
FIGURE 32. EL1508CL HARMONIC DISTORTION TEST
(FULL POWER MODE)
FREQ=1MHz
VS=±12V
RSET=6.81kΩ
RL=100Ω
GAIN=10
-20
4
3
VOUTP-P (V)
FIGURE 31. EL1508CM HARMONIC DISTORTION vs
DIFFERENTIAL OUTPUT VOLTAGE
(FULL POWER MODE)
0
HD3
-50
-90
9
8
FREQ=1MHz
VS=±5V
RSET=6.81kΩ
RL=100Ω
GAIN=10
-10
10
15
20
25
FREQ=1MHz
VS=±12V
RSET=6.81kΩ
RL=100Ω
GAIN=10
-20
HD3
-40
-60
HD2
-80
-100
0
VOUTP-P (V)
5
10
15
20
25
VOUTP-P (V)
FIGURE 33. EL1508CM HARMONIC DISTORTION vs
DIFFERENTIAL OUTPUT VOLTAGE
(FULL POWER MODE)
VOUT
FIGURE 34. EL1508CL HARMONIC DISTORTION TEST
(FULL POWER MODE)
VOUT
C0, C1
C0, C1
2V/DIV
2V/DIV
40ns/DIV
FIGURE 35. DISABLE TIME
11
40ns/DIV
FIGURE 36. ENABLE TIME
FN7014.5
March 26, 2007
EL1508
Typical Performance Curves
(Continued)
25
21.4
21
21.2
17
IS+ (mA)
OUTPUT VOLTAGE P-P (V)
21.6
21.0
FREQ=100kHz
VS=±12V
RSET=0
AV=10
20.8
20.6
50
70
110
90
130
150
170
VS=±12V
RFB=10
AV=10
RL=100Ω
13
9
5
190
0
2
4
8
10
RADJ (kΩ)
DIFFERENTIAL LOAD RESISTANCE (Ω)
FIGURE 37. LOAD RESISTANCE vs OUTPUT VOLTAGE
(ALL POWER MODES)
FIGURE 38. IS+ vs RADJ (FULL POWER MODE)
30
4.5
25
FU LL P
-
20
2/3 POW
15
10
4.0
+
OWE R
POWER DISSIPATION (W)
SUPPLY CURRENT (mA)
6
+
ER
-
1/3 POWER
+
-
5
θJA = 30°C/W
3.5
3.0
2.5
θJA = 43°C/W
2.0
θJA = 53°C/W
1.5
θJA = 80°C/W
1.0
0.5
0
0
2
6
4
8
10
0
-40
12
-20
SUPPLY VOLTAGE (V)
FIGURE 39. SUPPLY CURRENT vs SUPPLY VOLTAGE
4
4.0
3.5
USING JEDEC JESD51-3 HIGH EFFECTIVE THERMAL
CONDUCTIVITY. (4-LAYER) TEST BOARD, QFN
EXPOSED DIEPAD SOLDERED TO PCB PER JESD51-5
3.5
POWER DISSIPATION (W)
POWER DISSIPATION (W)
100
FIGURE 40. POWER DISSIPATION vs AMBIENT
TEMPERATURE for VARIOUS MOUNTED θJAs
(See Thermal Resistance Curve on page 15)
USING ELANTEC EL1503CS DEMO BOARD, 2”X2”
(4-LAYER). DEMO BOARD WITH HEATSINK VIA
INTERNAL GROUND PLANE
3
θJ
2.5
A =4
2
7°
C/
W
1.5
1
0.5
0
-40
20
40
60
80
0
AMBIENT TEMPERATURE (°C)
3.0 3.378W
θ
JA
=
2.5
37
°C
/W
2.0
1.5
1.0
0.5
0
-20
0
20
40
60
80
100
AMBIENT TEMPERATURE (°C)
FIGURE 41. 16 LD SOIC POWER DISSIPATION and THERMAL
RESISTANCE
12
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
FIGURE 42. 24 LD QFN POWER DISSIPATION vs AMBIENT
TEMPERATURE
FN7014.5
March 26, 2007
EL1508
Applications Information
The EL1508 consists of two high-power line driver amplifiers
that can be connected for full duplex differential line
transmission. The amplifiers are designed to be used with
signals up to 4MHz and produce low distortion levels. The
EL1508 has been optimized as a line driver for ADSL CO
application. The driver output stage has been sized to
provide full ADSL CO power level of 20dBM onto the
telephone lines. Realizing that the actual peak output
voltages and currents vary with the line transformer turns
ratio, the EL1508 is designed to support 450mA of output
current which exceeds the level required for 1:2 transformer
ratio. A typical ADSL interface circuit is shown in Figure 43
below. Each amplifier has identical positive gain
connections, and optimum common-mode rejection occurs.
Further, DC input errors are duplicated and create commonmode rather than differential line errors.
DRIVER
INPUT+
+
-
ROUT
LINE +
RF
ZLINE
2RG
RF
DRIVER
INPUT-
ROUT
+
LINE RF
+
RECEIVE
OUT +
RECEIVE
AMPLIFIERS
RECEIVE
OUT -
+
RF
R
RIN
the average output current, IO, or 1/2 IQ, whichever is the
lowest. We’ll call this term IX.
Therefore, we can determine a quiescent current with the
equation:
P Dquiescent = V S × ( I S – 21 X )
where:
VS is the supply voltage (VS+ to VS-)
IS is the operating supply current (IS+ - IS-) / 2
IX is the lesser of IO or 1/2 IQ
The dissipation in the output stage has two main
contributors. Firstly, we have the average voltage drop
across the output transistor and secondly, the average
output current. For minimal power dissipation, the user
should select the supply voltage and the line transformer
ratio accordingly. The supply voltage should be kept as low
as possible, while the transformer ratio should be selected
so that the peak voltage required from the EL1508 is close to
the maximum available 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:
VS
P Dtransistors = 2 × I O × ⎛ ------- – V O⎞
⎝ 2
⎠
R
RIN
where:
VS is the supply voltage (VS+ to VS-)
FIGURE 43. TYPICAL LINE INTERFACE CONNECTION
VO is the average output voltage per channel
IO is the average output current per channel
Input Connections
The EL1508 amplifiers are somewhat sensitive to source
impedance. In particular, they do not like being driven by
inductive sources. More than 100nH of source impedance
can cause ringing or even oscillations. This inductance is
equivalent to about 4” of unshielded wiring, or 6” of
unterminated transmission line. Normal high-frequency
construction obviates any such problem.
Power Supplies and Dissipation
Due to the high power drive capability of the EL1508, much
attention needs to be paid to power dissipation. The power
that needs to be dissipated in the EL1508 has two main
contributors. The first is the quiescent current dissipation.
The second is the dissipation of the output stage.
The quiescent power in the EL1508 is not constant with
varying outputs. In reality, 50% of the total quiescent supply
current needed to power each driver is converted in to output
current. Therefore, in the equation below we should subtract
13
The overall power dissipation (PDISS) is obtained by adding
PDquiescent and PDtransistor.
Estimating Line Driver Power Dissipation in ADSL
CO Applications
Figure 44 on the following page shows a typical ADSL CO
line driver implementation. The average line power
requirement for the ADSL CO application is 20dBM
(100mW) into a 100Ω line. The average line voltage is
3.16VRMS. The ADSL 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 100Ω, the
average voltage is 3.16VRMA and the average current is
31.6mA. The power dissipated in the EL1508 is a
FN7014.5
March 26, 2007
EL1508
combination of the quiescent power and the output stage
power when driving the line:
PCB Layout Considerations for QFN and SOIC
Packages
Pd = P quiescent + P output-stage
The EL1508 die is packaged in three different thermallyefficient packages: a 20 Ld SOIC (0.300”), a 16 Ld SOIC
(0.150”), and a 24 Ld QFN. The 16 Ld SOIC has the same
external dimensions as a standard 0.150” width SOIC
package, but has the center four leads (two per side)
internally-fused for heat transfer purposes. Both packages
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 XDSL 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 are shown in the figures below that result in thermal
resistance θJA of 37°C/W for the QFN package and 47°C/W
for the SOIC package. The thermal resistance is obtained
with the EL1508CL and CS demo boards. The demo board
is a 4-layer board built with 2oz. copper and has a dimension
of 4in2. Note, the user must follow the thermal layout
guideline to achieve these results. In addition to lower
thermal resistance, the QFN package exhibits much lower
2nd harmonic distortion.
Pd = V S × I Q + ( V S – 2 × V OUT-RMS ) × I OUT-RMS
In the full power mode and with 6.8k RADJ registers, the
EL1508 consumes typically 7mA quiescent current 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:
Pd = 12 × ( 7mA × 50% ) + ( 12V – 3.16 ) × 31.6mA × 2
where:
Pd = 598mW
The θJA requirement needs to be calculated. This is done
using the equation:
T JUNCT – T AMB
Θ JA = -------------------------------------------P DISS
where:
A separate Application Note for the QFN package and layout
recommendations is also available.
TJUNCT is the maximum die temperature (150°C)
TAMB is the maximum ambient temperature (85°C)
PDISS is the dissipation calculated above
θJA is the junction to ambient thermal resistance for the
package when mounted on the PCB
150 – 85
Θ JA = ---------------------- = 108°C/W
598mW
TX+
FROM
AFE
+
-
VS+
RT
VS-
10 0.22µF
RF
2RG
TXFR 1:1
100
3k
TOP (24 LD QFN)
1.5kΩ
TX-
VS+
RT
VSRF
10
+
-
0.22µF
3k
FIGURE 44. TYPICAL ADSL CO LINE DRIVER
IMPLEMENTATION
INTERNAL GROUND PLANE (24 LD QFN)
14
FN7014.5
March 26, 2007
EL1508
MOUNTED DEVICE θJA (°C/W)
55
Note: 2OZ COPPER USED
TOP FOIL ONLY-WITH SOLDER MASK
50
TOP FOIL-WITH 0.45in2
BOTTOM FOIL WITH MANY
FEEDTHROUGHS
45
40
TOP FOIL ONLY-NO SOLDER MASK
35
30
0
2
4
6
8
10
AREA OF CIRCUIT BOARD HEAT SINK (in2)
TOP (16 Ld SO)
FIGURE 45. THERMAL RESISTANCE of 20 LD SO (0.300")
EL1508 vs BOARD COPPER AREA
Power Control Function
The EL1508 contains two forms of power control operation.
Two digital inputs, C0 and C1, can be used to control the
supply current of the EL1508 drive amplifiers. As the supply
current is reduced, the EL1508 will start to exhibit slightly
higher levels of distortion and the frequency response will be
limited. The 4 power modes of the EL1508 are set up as
shown in the following table:
TABLE 1. POWER MODES OF THE EL1508
C1
C0
0
0
IS full power mode
0
1
2/3 IS power mode
EL1508CM PCB Layout Considerations
1
0
1/3 IS power mode
The 20 Ld SOIC (0.300") Power Package is designed so that
heat may be conducted away from the device in an efficient
manner. To disperse this heat, the center four leads on either
side of the package are internally fused to the mounting
platform of the die. Heat flows through the leads into the
circuit board copper, then spreads and convects to air. Thus,
the ground plane on the component side of the board
becomes the heatsink. This has proven to be a very effective
technique, but several aspects of board layout should be
noted. First, the heat should not be shunted to internal
copper layers of the board nor backside foil, since the
feedthroughs and fiberglass of the board are not very
thermally conductive. To obtain the best thermal resistance
of the mounted part, θJA, the topside copper ground plane
should have as much area as possible and be as thick as
practical. If possible, the solder mask should be cut away
from the EL1508 to improve thermal resistance. Finally,
metal heatsinks can be placed against the board close to the
part to draw heat toward the chassis. The graph below
shows various θJAs for the 20 Ld SOIC mounted on different
copper foil areas.
1
1
Power-down
INTERNAL GROUND PLANE (16 Ld SO)
15
OPERATION
Another method for controlling the power consumption of the
EL1508 is to connect a resistor from the IADJ pin to ground.
When the IADJ pin is grounded (the normal state), the supply
current per channel is as per the specifications table on page
2. When a resistor is inserted, the supply current is scaled
according to the “RSET vs IS” graphs in the Performance
Curves section.
Both methods of power control can be used simultaneously.
In this case, positive and negative supply currents (per amp)
are given by the equations below:
12.4mA
I S + = 0.9mA + ------------------------------------------------------ × ( 2/3C 1 + 1/3C 0 )
( 1 + R SET ÷ 1574Ω )
12.4mA
I S - = ------------------------------------------------------ × ( 2/3C 1 + 1/3C 0 )
( 1 + R SET ÷ 1574Ω )
Output Loading
While the drive amplifiers can output in excess of 500mA
transiently, the internal metallization is not designed to carry
more than 100mA of steady DC current and there is no
FN7014.5
March 26, 2007
EL1508
current-limit mechanism. This allows safely driving rms
sinusoidal currents of 2 x 100mA, or 200mA. This current is
more than that required to drive line impedances to large
output levels, but output short circuits cannot be tolerated.
The series output resistor will usually limit currents to safe
values in the event of line shorts. Driving lines with no series
resistor is a serious hazard.
The amplifiers are sensitive to capacitive loading. More than
25pF will cause peaking of the frequency response. The
same is true of badly terminated lines connected without a
series matching resistor.
Output AC Coupling
When in power-down mode, several volts of differential
voltage may appear across the line driver outputs. If DC
current path exists between the two outputs, large DC
current can flow from the positive supply rail to the negative
supply rail through the outputs. To avoid DC current flow, the
most effective solution is to place DC blocking capacitors in
series at the outputs, as shown by the 0.22µF capacitors in
Figure 44.
Single Supply Operation
The EL1508 can also be powered from a single supply
voltage. When operating in this mode, the GND pins can still
be connected directly to GND. To calculate power
dissipation, the equations in the previous section should be
used, with VS equal to half the supply rail.
Feedback Resistor Value
The bandwidth and peaking of the amplifiers varies with
supply voltage somewhat and with gain settings. The
feedback resistor values can be adjusted to produce an
optimal frequency response. Here is a series of resistor
values that produce an optimal driver frequency response
(1dB peaking) for different supply voltages and gains:
TABLE 2. OPTIMUM DRIVER FEEDBACK RESISTOR FOR
VARIOUS GAINS AND SUPPLY VOLTAGES
DRIVER VOLTAGE GAIN
SUPPLY
VOLTAGE
2.5
5
10
±5V
3.5k
3.25k
3k
±12V
3.5k
3.25k
3k
Power Supplies
The power supplies should be well bypassed close to the
EL1508. A 2.2µF tantalum capacitor and a 0.1µF ceramic
capacitor for each supply works well. Since the load currents
are differential, they should not travel through the board
copper and set up ground loops that can return to amplifier
inputs. Due to the class AB output stage design, these
currents have heavy harmonic content. If the ground
terminal of the positive and negative bypass capacitors are
connected to each other directly and then returned to circuit
ground, no such ground loops will occur. This scheme is
employed in the layout of the EL1508 demonstration board,
and documentation can be obtained from the factory.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
16
FN7014.5
March 26, 2007
EL1508
Small Outline Package Family (SO)
A
D
h X 45°
(N/2)+1
N
A
PIN #1
I.D. MARK
E1
E
c
SEE DETAIL “X”
1
(N/2)
B
L1
0.010 M C A B
e
H
C
A2
GAUGE
PLANE
SEATING
PLANE
A1
0.004 C
0.010 M C A B
L
b
0.010
4° ±4°
DETAIL X
MDP0027
SMALL OUTLINE PACKAGE FAMILY (SO)
INCHES
SYMBOL
SO-14
SO16 (0.300”)
(SOL-16)
SO20
(SOL-20)
SO24
(SOL-24)
SO28
(SOL-28)
TOLERANCE
NOTES
A
0.068
0.068
0.068
0.104
0.104
0.104
0.104
MAX
-
A1
0.006
0.006
0.006
0.007
0.007
0.007
0.007
±0.003
-
A2
0.057
0.057
0.057
0.092
0.092
0.092
0.092
±0.002
-
b
0.017
0.017
0.017
0.017
0.017
0.017
0.017
±0.003
-
c
0.009
0.009
0.009
0.011
0.011
0.011
0.011
±0.001
-
D
0.193
0.341
0.390
0.406
0.504
0.606
0.704
±0.004
1, 3
E
0.236
0.236
0.236
0.406
0.406
0.406
0.406
±0.008
-
E1
0.154
0.154
0.154
0.295
0.295
0.295
0.295
±0.004
2, 3
e
0.050
0.050
0.050
0.050
0.050
0.050
0.050
Basic
-
L
0.025
0.025
0.025
0.030
0.030
0.030
0.030
±0.009
-
L1
0.041
0.041
0.041
0.056
0.056
0.056
0.056
Basic
-
h
0.013
0.013
0.013
0.020
0.020
0.020
0.020
Reference
-
16
20
24
28
Reference
-
N
SO-8
SO16
(0.150”)
8
14
16
Rev. M 2/07
NOTES:
1. Plastic or metal protrusions of 0.006” maximum per side are not included.
2. Plastic interlead protrusions of 0.010” maximum per side are not included.
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994
17
FN7014.5
March 26, 2007
EL1508
QFN (Quad Flat No-Lead) Package Family
MDP0046
QFN (QUAD FLAT NO-LEAD) PACKAGE FAMILY
(COMPLIANT TO JEDEC MO-220)
A
MILLIMETERS
D
N
(N-1)
(N-2)
B
1
2
3
PIN #1
I.D. MARK
E
(N/2)
2X
0.075 C
2X
0.075 C
N LEADS
TOP VIEW
0.10 M C A B
(N-2)
(N-1)
N
b
L
SYMBOL QFN44 QFN3
TOLERANCE
NOTES
A
0.90
0.90
0.90
0.90
±0.10
-
A1
0.02
0.02
0.02
0.02
+0.03/-0.02
-
b
0.25
0.25
0.23
0.22
±0.02
-
c
0.20
0.20
0.20
0.20
Reference
-
D
7.00
5.00
8.00
5.00
Basic
-
Reference
8
Basic
-
Reference
8
Basic
-
D2
5.10
3.80
5.80 3.60/2.48
E
7.00
7.00
8.00
1
2
3
6.00
E2
5.10
5.80
5.80 4.60/3.40
e
0.50
0.50
0.80
0.50
L
0.55
0.40
0.53
0.50
±0.05
-
N
44
38
32
32
Reference
4
ND
11
7
8
7
Reference
6
NE
11
12
8
9
Reference
5
MILLIMETERS
PIN #1 I.D.
3
QFN32
SYMBOL QFN28 QFN2
QFN20
QFN16
A
0.90
0.90
0.90
0.90
0.90
±0.10
-
A1
0.02
0.02
0.02
0.02
0.02
+0.03/
-0.02
-
b
0.25
0.25
0.30
0.25
0.33
±0.02
-
c
0.20
0.20
0.20
0.20
0.20
Reference
-
D
4.00
4.00
5.00
4.00
4.00
Basic
-
D2
2.65
2.80
3.70
2.70
2.40
Reference
-
(E2)
(N/2)
NE 5
7
(D2)
BOTTOM VIEW
0.10 C
e
C
SEATING
PLANE
TOLERANCE NOTES
E
5.00
5.00
5.00
4.00
4.00
Basic
-
E2
3.65
3.80
3.70
2.70
2.40
Reference
-
e
0.50
0.50
0.65
0.50
0.65
Basic
-
L
0.40
0.40
0.40
0.40
0.60
±0.05
-
N
28
24
20
20
16
Reference
4
ND
6
5
5
5
4
Reference
6
NE
8
7
5
5
4
Reference
5
Rev 11 2/07
0.08 C
N LEADS
& EXPOSED PAD
SEE DETAIL "X"
NOTES:
1. Dimensioning and tolerancing per ASME Y14.5M-1994.
2. Tiebar view shown is a non-functional feature.
SIDE VIEW
3. Bottom-side pin #1 I.D. is a diepad chamfer as shown.
4. N is the total number of terminals on the device.
(c)
C
5. NE is the number of terminals on the “E” side of the package
(or Y-direction).
2
A
(L)
A1
N LEADS
DETAIL X
6. ND is the number of terminals on the “D” side of the package
(or X-direction). ND = (N/2)-NE.
7. Inward end of terminal may be square or circular in shape with radius
(b/2) as shown.
8. If two values are listed, multiple exposed pad options are available.
Refer to device-specific datasheet.
18
FN7014.5
March 26, 2007