AD ADA4850-2YCPZ-R2 High speed, rail-to-rail output, op amp with ultralow power-down Datasheet

High Speed, Rail-to-Rail Output,
Op Amp with Ultralow Power-Down
ADA4850-1/ADA4850-2
PIN CONFIGURATIONS
Ultralow power-down current: 150 nA/amp max
Low quiescent current: 2.4 mA/amp
High speed
175 MHz −3 dB bandwidth
220 V/µs slew rate
85 ns settling time to 0.1%
Excellent video specifications
0.1 dB flatness: 14 MHz
Differential gain: 0.12%
Differential phase: 0.09°
Single-supply operation: 2.7 V to 6 V
Rail-to-rail output
Output swings to within 80 mV of either rail
Low voltage offset: 0.6 mV
ADA4850-1
POWER DOWN 1
8 +VS
NC 2
7 OUTPUT
–IN 3
6 NC
+IN 4
5 –VS
05320-106
FEATURES
NC = NO CONNECT
14 PD1
13 PD2
15 NC
16 NC
Figure 1. 8-Lead, 3 mm × 3 mm LFCSP
ADA4850-2
12 +VS
VOUT1 1
APPLICATIONS
Portable multimedia players
Video cameras
Digital still cameras
Consumer video
–IN1 2
11 VOUT2
+IN1 3
10 –IN2
–VS 4
+IN2
05320-043
NC 8
NC 6
NC 7
NC 5
9
NC = NO CONNECT
Figure 2. 16-Lead, 3 mm × 3 mm LFCSPP
GENERAL DESCRIPTION
2
1
The ADA4850 family provides users with a true single-supply
capability, allowing input signals to extend 200 mV below the
negative rail and to within 2.2 V of the positive rail. The output
of the amplifier can swing within 80 mV of either supply rail.
0
–1
–2
–3
–4
G = +1
VS = 5V
RL = 1kΩ
VOUT = 0.1V p-p
–5
–6
1
10
100
1000
FREQUENCY (MHz)
With its combination of low price, excellent differential gain
(0.12%), differential phase (0.09º), and 0.1 dB flatness out to
14 MHz, these amplifiers are ideal for video applications.
Figure 3. Small Signal Frequency Response
1
Patent pending.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2005 Analog Devices, Inc. All rights reserved.
05320-054
The ADA4850-1/ADA4850-2 are designed to operate at supply
voltages as low as 2.7 V and up to 6 V at 2.4 mA of supply
current per amplifier. In power-down mode, the supply current
is less than 150 nA, ideal for battery-powered applications.
The ADA4850-1/ADA4850-2 are designed to work in the
extended temperature range of −40°C to +125°C.
CLOSED-LOOP GAIN (dB)
The ADA4850-1, ADA4850-21 are low price, high speed,
voltage feedback rail-to-rail output op amps with ultralow
power-down. Despite their low price, the ADA4850-1/
ADA4850-2 provide excellent overall performance and
versatility. The 175 MHz −3 dB bandwidth and 220 V/µs
slew rate make these amplifiers well-suited for many generalpurpose, high speed applications.
ADA4850-1/ADA4850-2
TABLE OF CONTENTS
Specifications with +3 V Supply ..................................................... 3
Headroom and Overdrive Recovery Considerations ............ 12
Specifications with +5 V Supply ..................................................... 4
Operating the ADA4850-1/ADA4850-2 on
Bipolar Supplies .......................................................................... 13
Absolute Maximum Ratings............................................................ 5
Thermal Resistance ...................................................................... 5
ESD Caution.................................................................................. 5
Typical Performance Characteristics ............................................. 6
Power-Down Pins....................................................................... 13
Outline Dimensions ....................................................................... 14
Ordering Guide .......................................................................... 14
Circuit Description......................................................................... 12
REVISION HISTORY
4/05—Rev. 0 to Rev. A
AddedADA4850-1..............................................................Universal
Added 8-Lead LFCSP.........................................................Universal
Changes to Features.......................................................................... 1
Changes to General Description .................................................... 1
Changes to Figure 3.......................................................................... 1
Changes to Table 1............................................................................ 3
Changes to Table 2............................................................................ 4
Changes to Power-Down Pins Section and Table 5 ................... 13
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 14
2/05—Revision 0: Initial Version
Rev. A | Page 2 of 16
ADA4850-1/ADA4850-2
SPECIFICATIONS WITH +3 V SUPPLY
TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.
Table 1.
Parameter
DYNAMIC PERFORMANCE
−3 dB Bandwidth
Bandwidth for 0.1 dB Flatness
Slew Rate
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Harmonic Distortion (dBc) HD2/HD3
Input Voltage Noise
Input Current Noise
Differential Gain
Differential Phase
DC PERFORMANCE
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
Input Bias Current Drift
Input Bias Offset Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
Input Common-Mode Voltage Range
Input Overdrive Recovery Time (Rise/Fall)
Common-Mode Rejection Ratio
POWER-DOWN
Power-Down Input Voltage
Turn-Off Time
Turn-On Time
Power-Down Bias Current/ Power Down Pin
Enabled
Power-Down
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time (Rise/Fall)
Output Voltage Swing
Short-Circuit Current
POWER SUPPLY
Operating Range1
Quiescent Current/Amplifier
Quiescent Current (Power-Down)/Amplifier
Positive Power Supply Rejection
Negative Power Supply Rejection
1
Conditions
Min
Typ
Max
Unit
G = +1, VO = 0.1 V p-p
G = +2, VO = 0.5 V p-p, RL = 150 Ω
G = +2, VO = 0.5 V p-p, RL = 150 Ω
G = +2, VO = 1 V Step
G = +2, VO = 1 V Step, RL = 150 Ω
160
45
14
110
80
MHz
MHz
MHz
V/µs
ns
fC = 1 MHz, VO = 2 V p-p, G = +3, RL = 150 Ω
f = 100 kHz
f = 100 kHz
G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p
G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p
−72/−77
10
2.5
0.2
0.2
dBc
nV/√Hz
pA/√Hz
%
Degrees
VO = 0.25 V to 0.75 V
78
0.6
4
2.4
4
30
100
−76
0.5/5.0
1.2
−0.2 to +0.8
60/50
−108
MΩ
pF
V
ns
dB
Power-down ADA4850-1/ADA4850-2
Enabled ADA4850-1/ADA4850-2
<0.7/<0.6
>0.8/>1.7
0.7
60
V
V
µs
ns
Power-down = 3 V
Power-down = 0 V
37
0.01
Differential/common-mode
VIN = +3.5 V to −0.5 V, G = +1
VCM = 0.5 V
VIN = +0.7 V to −0.1 V, G = +5
0.06 to 2.83
Sinking/sourcing
For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section.
Rev. A | Page 3 of 16
−83
−83
4.4
55
0.2
70/100
0.03 to 2.92
105/74
2.7
+VS = +3 V to +4 V, −VS = 0 V
+VS = +3 V, −VS = 0 V to –1 V
4.1
2.4
15
−100
−102
mV
µV/°C
µA
nA/°C
nA
dB
µA
µA
ns
V
mA
6
2.8
150
V
mA
nA
dB
dB
ADA4850-1/ADA4850-2
SPECIFICATIONS WITH +5 V SUPPLY
TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.
Table 2.
Parameter
DYNAMIC PERFORMANCE
−3 dB Bandwidth
Bandwidth for 0.1 dB Flatness
Slew Rate
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Harmonic Distortion (dBc) HD2/HD3
Input Voltage Noise
Input Current Noise
Differential Gain
Differential Phase
Crosstalk(RTI)-ADA4850-2
DC PERFORMANCE
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
Input Bias Current Drift
Input Bias Offset Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
Input Common-Mode Voltage Range
Input Overdrive Recovery Time (Rise/Fall)
Common-Mode Rejection Ratio
POWER-DOWN
Power-Down Input Voltage
Turn-Off Time
Turn-On Time
Power-Down Bias Current/ Power Down Pin
Enabled
Power-Down
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time (Rise/Fall)
Output Voltage Swing
Short-Circuit Current
POWER SUPPLY
Operating Range1
Quiescent Current/Amplifier
Quiescent Current (Power-Down)/Amplifier
Positive Power Supply Rejection
Negative Power Supply Rejection
1
Conditions
Min
Typ
Max
Unit
G = +1, VO = 0.1 V p-p
G = +1, VO = 0.5 V p-p
G = +2, VO = 1.4 V p-p, RL = 150 Ω
G = +2, VO = 4 V Step
G = +2, VO = 2 V Step
G = +2, VO = 1 V Step, RL = 150 Ω
175
110
9
220
160
85
MHz
MHz
MHz
V/µs
V/µs
ns
fC = 1 MHz, VO = 2 V p-p, G = +2, RL = 150 Ω
f = 100 kHz
f = 100 kHz
G = +3, NTSC, RL = 150 Ω
G = +3, NTSC, RL = 150 Ω
f = 4.5 MHz, RL = 150 Ω, VO = 2 V p-p
−81/−86
10
2.5
0.12
0.09
60
dBc
nV/√Hz
pA/√Hz
%
Degrees
dB
VO = 2.25 V to 2.75 V
83
0.6
4
2.3
4
30
105
−85
0.5/5.0
1.2
−0.2 to +2.8
50/40
−110
MΩ
pF
V
ns
dB
Power-down ADA4850-1/ADA4850-2
Enabled ADA4850-1/ADA4850-2
<0.7/<0.6
>0.8/>1.7
0.7
50
V
V
µs
ns
Power-down = 5 V
Power-down = 0 V
0.05
0.02
Differential/common-mode
VIN = +5.5 V to −0.5 V, G = +1
VCM = 2.0 V
VIN = +1.1 V to −0.1 V, G = +5
0.14 to 4.83
Sinking/sourcing
For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section.
Rev. A | Page 4 of 16
−84
−84
4.2
0.13
0.2
60/70
0.07 to 4.92
118/94
2.7
+VS = +5 V to +6 V, −VS = 0 V
+VS = +5 V, −VS = −0 V to −1 V
4.2
2.5
15
−100
−102
mV
µV/°C
µA
nA/°C
nA
dB
mA
µA
ns
V
mA
6
2.9
150
V
mA
nA
dB
dB
ADA4850-1/ADA4850-2
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Supply Voltage
Power Dissipation
Power Down Pin Voltage
Common-Mode Input Voltage
Differential Input Voltage
Storage Temperature
Operating Temperature Range
Lead Temperature Range
(Soldering 10 sec)
Junction Temperature
Rating
12.6 V
See Figure 4
(−VS + 6) V
(−VS − 0.5 ) V to (+VS + 0.5) V
+VS to −VS
−65°C to +125°C
−40°C to +125°C
300°C
150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, θJA is
specified for the device soldered in the circuit board for surfacemount packages.
Table 4. Thermal Resistance
Package Type
16-Lead LFCSP
8-Lead LFCSP
θJA
91
80
The power dissipated in the package (PD) is the sum of the
quiescent power dissipation and the power dissipated in the die
due to the ADA4850-1/ADA4850-2 drive at the output. The
quiescent power is the voltage between the supply pins (VS)
times the quiescent current (IS).
PD = Quiescent Power + (Total Drive Power − Load Power)
⎛V V
PD = (VS × I S ) + ⎜⎜ S × OUT
RL
⎝ 2
⎞ VOUT 2
⎟–
⎟
RL
⎠
RMS output voltages should be considered. If RL is referenced
to −VS, as in single-supply operation, the total drive power is
VS × IOUT. If the rms signal levels are indeterminate, consider
the worst case, when VOUT = VS/4 for RL to midsupply.
PD = (VS × I S ) +
(VS /4 )2
RL
In single-supply operation with RL referenced to −VS, the worst
case is VOUT = VS/2.
Airflow increases heat dissipation, effectively reducing θJA.
Also, more metal directly in contact with the package leads and
exposed paddle from metal traces, through holes, ground, and
power planes reduce θJA.
Figure 4 shows the maximum safe power dissipation in the
package vs. the ambient temperature for the LFCSP (91°C/W)
package on a JEDEC standard 4-layer board. θJA values are
approximations.
Unit
°C/W
°C/W
2.5
2.0
LFCSP-8
LFCSP-16
1.5
1.0
0.5
0
–55 –45 –35 –25 –15 –5
5
15 25 35 45 55 65 75 85 95 105 115 125
AMBIENT TEMPERATURE (°C)
05320-055
The maximum safe power dissipation for the ADA4850-1/
ADA4850-2 is limited by the associated rise in junction
temperature (TJ) on the die. At approximately 150°C, which is
the glass transition temperature, the plastic changes its
properties. Even temporarily exceeding this temperature limit
may change the stresses that the package exerts on the die,
permanently shifting the parametric performance of the
ADA4850-1/ADA4850-2. Exceeding a junction temperature of
150°C for an extended period of time can result in changes in
silicon devices, potentially causing degradation or loss of
functionality.
MAXIMUM POWER DISSIPATION (W)
Maximum Power Dissipation
Figure 4. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate
on the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. A | Page 5 of 16
ADA4850-1/ADA4850-2
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted.
4
0
VS = 5V
RL = 150Ω
VOUT = 0.1V p-p
–1
G = –1
CLOSED-LOOP GAIN (dB)
2
G = +2
–2
–3
G = +10
–4
1
0
1pF
–1
0pF
–2
–3
–4
–5
1
10
100
FREQUENCY (MHz)
–6
1
10
100
Figure 8. Small Signal Frequency Response for Various Capacitor Loads
Figure 5. Small Signal Frequency Response for Various Gains
6.2
2
1
6.0
–1
5.9
GAIN (dB)
0
RL = 1kΩ
–2
VS = 5V
G = +2
RL = 150Ω
6.1
RL = 150Ω
VS = 5V, VOUT = 2V p-p
5.8
VS = 5V, VOUT = 1.4V p-p
VS = 3V, VOUT = 0.5V p-p
5.7
–3
VS = 5V, VOUT = 0.1V p-p
5.6
–4
VS = 5V
G = +1
VOUT = 0.1V p-p
–6
10
100
1000
FREQUENCY (MHz)
5.4
100k
1M
Figure 6. Small Signal Frequency Response for Various Loads
Figure 9. 0.1 dB Flatness Response
3
1
2
0
VS = 5V
G = +1
VOUT = 0.5V p-p
VS = 3V
CLOSED-LOOP GAIN (dB)
1
0
–1
VS = 5V
–2
–3
–4
G = +1
RL = 150Ω
VOUT = 0.1V p-p
–6
1
–1
RL = 150Ω
–2
RL = 1kΩ
–3
–4
–5
–6
10
100
1000
FREQUENCY (MHz)
05320-046
–5
100M
10M
FREQUENCY (Hz)
–7
1
10
100
1000
FREQUENCY (MHz)
Figure 10. Large Frequency Response for Various Loads
Figure 7. Small Signal Frequency Response for Various Supplies
Rev. A | Page 6 of 16
05320-048
1
05320-047
5.5
05320-045
–5
CLOSED-LOOP GAIN (dB)
300
FREQUENCY (MHz)
05320-007
–5
–6
CLOSED-LOOP GAIN (dB)
6pF
G = +1
VS = 5V
RL = 1kΩ
VOUT = 0.1V p-p
3
05320-044
NORMALIZED CLOSED-LOOP GAIN (dB)
1
ADA4850-1/ADA4850-2
3
300
VS = 3V
G = +1
RL = 1kΩ
VOUT = 0.1V p-p
G = +2
VS = 5V
RL = 1kΩ
250
+85°C
0
+25°C
–1
–40°C
–2
200
POSITIVE SLEW RATE
150
100
–3
1
10
1000
100
0
05320-057
–5
FREQUENCY (MHz)
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
OUTPUT VOLTAGE STEP (V)
Figure 11. Small Signal Frequency Response for Various Temperatures
05320-024
50
–4
Figure 14. Slew Rate vs. Output Voltage
3
10k
VS = 5V
G = +1
RL = 1kΩ
VOUT = 0.1V p-p
2
+125°C
1k
1
+85°C
SUPPLY CURRENT (µA)
CLOSED-LOOP GAIN (dB)
NEGATIVE SLEW RATE
1
SLEW RATE (V/µs)
CLOSED-LOOP GAIN (dB)
2
+125°C
0
–1
+25°C
–2
–40°C
–3
VS = 3V, 5V, ADA4850-2
100
VS = 3V, 5V, ADA4850-1 ENABLE
10
VS = 3V, 5V, ADA4850-1 POWER DOWN
1
1
10
1000
100
0.1
05320-098
–5
FREQUENCY (MHz)
0.5
0
0
–30
100
–60
–150
40
GAIN
20
–180
0
–210
CROSSTALK (dB)
–120
60
OPEN-LOOP PHASE (Degrees)
–90
3.0
3.5
4.0
4.5
5.0
G = +2
VS = 5V
RL = 150Ω
VOUT = 2V p-p
–60
VOUT2 TO VOUT1
–70
–80
VOUT1 TO VOUT2
–20
10
100
1k
10k
100k
1M
10M
100M
FREQUENCY (Hz)
–240
1G
–100
100k
1M
10M
FREQUENCY (Hz)
Figure 16. Crosstalk vs. Frequency
Figure 13. Open-Loop Gain and Phase vs. Frequency
Rev. A | Page 7 of 16
100M
05320-037
–90
05320-012
OPEN-LOOP GAIN (dB)
PHASE
2.5
–40
–50
80
2.0
Figure 15. Supply Current vs. Power-Down Voltage
VS = 5V
120
1.5
POWER-DOWN VOLTAGE (V)
Figure 12. Small Signal Frequency Response for Various Temperatures
140
1.0
05320-036
–4
ADA4850-1/ADA4850-2
–40
2.575
G = +1
VS = 5V
VOUT = 500mV p-p
OUTPUT VOLTAGE (V)
–60
RL = 1kΩ HD2
RL = 150Ω HD2
RL = 1kΩ HD3
–110
0.1
1
100
10
FREQUENCY (MHz)
2.425
0
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
VOUT = 200mV p-p
HD2
–90
VOUT = 200mV p-p
HD3
–100
VOUT = 500mV p-p
HD3
–120
0.1
1
100
10
80
100
120
140
160
180
200
FREQUENCY (MHz)
G = +2
RL = 1kΩ
VS = 5V
3.00
2.75
2.50
2.25
2.00
1.75
05320-103
0
50
100
150
200
TIME (ns)
Figure 18. Harmonic Distortion vs. Frequency for Various VOUT
Figure 21. Large Signal Transient Response
0.65
0.875
2.875
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
G = +2
RL = 1kΩ
VS = 5V
0.55
0.50
0.45
0.40
G = +1
RL = 1kΩ
2.750
0.750
2.625
0.625
2.500
0.500
2.375
VS = 5V
0.375
0.250
2.250
0
50
100
150
200
TIME (ns)
05320-019
VS = 3V
0.35
Figure 19. Small Signal Transient Response for Various Supplies
2.125
0
50
100
150
0.125
200
TIME (ns)
Figure 22. Large Signal Transient Response for Various Supplies
Rev. A | Page 8 of 16
05320-049
HARMONIC DISTORTION (dBc)
VOUT = 500mV p-p
HD2
–110
OUTPUT VOLTAGE (V)
60
3.25
–70
0.60
40
Figure 20. Small Signal Transient Response for Capacitive Load
–50
–80
20
TIME (ns)
Figure 17. Harmonic Distortion vs. Frequency for Various Loads
G = +2
VS = 5V
–60 RL = 1kΩ
2.475
2.450
RL = 150Ω HD3
–100
2.500
05320-020
–90
2.525
05320-050
–80
0pF
OUTPUT VOLTAGE FOR 3V SUPPLY (V)
–70
10pF
G = +1
VS = 5V
RL = 150Ω
2.550
05320-102
HARMONIC DISTORTION (dBc)
–50
ADA4850-1/ADA4850-2
6
VOLTAGE NOISE (nV/ Hz)
5
VDISABLE
4
VOLTAGE (V)
1000
G = +2
VS = 5V
fIN = 400kHz
3
2
1
100
10
0
15
30
45
TIME (µs)
1
10
05320-025
0
100
10k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 23. Enable/Disable Time
Figure 26. Voltage Noise vs. Frequency
5.5
100
G = +1
VS = 5V
RL = 150Ω
f = 1MHz
5.0
INPUT
4.5
4.0
CURRENT NOISE (pA/ Hz)
INPUT AND OUTPUT VOLTAGE (V)
1k
05320-059
VOUT
–1
3.5
3.0
2.5
OUTPUT
2.0
1.5
1.0
10
0.5
200
300
400
500
600
700
800
900
1000
TIME (ns)
1
10
100
10k
100k
1M
10M
100M
1G
3
4
FREQUENCY (Hz)
Figure 24. Input Overdrive Recovery
Figure 27. Current Noise vs. Frequency
3.5
350
3.0
OUTPUT
G = +5
VS = 3V
RL = 150Ω
f = 1MHz
300
2.5
VS = 5V
N = 1720
x = 450µV
σ = 750µV
250
2.0
COUNT
5 × INPUT
1.5
200
150
1.0
100
0.5
50
0
–0.5
0
100
200
300
400
500
600
700
800
TIME (ns)
900
1000
05320-060
INPUT AND OUTPUT VOLTAGE (V)
1k
05320-095
100
05320-058
0
05320-065
0
–0.5
Figure 25. Output Overdrive Recovery
0
–4
–3
–2
–1
0
1
2
VOFFSET (mV)
Figure 28. Input Offset Voltage Distribution
Rev. A | Page 9 of 16
ADA4850-1/ADA4850-2
400
–1.2
+IB
380
VS = 5V
–1.4
INPUT BIAS CURRENT (µA)
360
320
300
280
260
240
–1.6
VS = 5V
–1.8
–IB
VS = 3V
–2.0
05320-092
–2.2
220
–0.5
0
0.5
1.0
1.5
2.0
2.5
3.5
3.0
–2.4
–40
05320-063
200
–1.0
VCM (V)
5
20
35
50
65
80
95
110
125
Figure 32. Input Bias Current vs. Temperature for Various Supplies
0.6
95
VS = 3V
0.5
+VSAT
0.4
0.3
–VSAT
VS = 5V
0.2
0.1
5
10
15
20
25
30
35
40
45
90
50
LOAD CURRENT (mA)
+VS – VOUT
85
80
–VS – VOUT
75
70
65
–40
05320-064
0
0
VS = 5V
RL = 1kΩ
OUTPUT SATURATION VOLTAGE (mV)
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
Figure 30. Output Saturation Voltage vs. Load Current
(Voltage Differential from Rails)
Figure 33. Output Saturation Voltage vs. Temperature
(Voltage Differential from Rails)
–30
4.9
–32
4.8
VS = 3V
VS = 5V
SUPPLY CURRENT (mA)
–34
–36
–38
–40
–42
4.7
4.6
VS = 3V
4.5
4.4
VS = 5V
–46
–40
05320-091
–44
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
4.3
4.2
–40
05320-090
OUTPUT SATURATION VOLTAGE (V)
–10
TEMPERATURE (°C)
Figure 29. Input Offset Voltage vs. Common-Mode Voltage
POWER-DOWN PIN BIAS CURRENT (µA)
–25
05320-062
VOS (µV)
340
–25
–10
5
20
35
50
65
80
95
110
TEMPERATURE (°C)
Figure 31. Power-Down Bias Current vs. Temperature for Various Supplies
Rev. A | Page 10 of 16
Figure 34. Current vs. Temperature for Various Supplies
125
ADA4850-1/ADA4850-2
–20
0
–10
–30
–20
–30
+PSR
–40
–50
–60
–PSR
–70
–80
–90
–40
–50
–70
–90
–100
–120
1k
100k
1M
10M
05320-094
–110
–110
100
10k
100M
FREQUENCY (Hz)
0.7
INPUT OFFSET VOLTAGE (mV)
0.6
0.5
VS = 5V
0.4
0.3
VS = 3V
0.2
0.1
05320-093
0
–25
–10
5
20
35
50
65
80
95
110
10k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 37. Common-Mode Rejection Ratio (CMRR) vs. Frequency
Figure 35. Power Supply Rejection (PSR) vs. Frequency
–0.1
–40
CHANNEL 2
–80
–100
1k
CHANNEL 1
–60
125
TEMPERATURE (°C)
Figure 36. Input Offset Voltage vs. Temperature for Various Supplies
Rev. A | Page 11 of 16
05320-034
COMMON-MODE REJECTION (dB)
POWER SUPPLY REJECTION (dB)
VS = 5V
VS = 5V
ADA4850-1/ADA4850-2
CIRCUIT DESCRIPTION
The ADA4850-1/ADA4850-2 feature a high slew rate input
stage that is a true single-supply topology, capable of sensing
signals at or below the negative supply rail. The rail-to-rail
output stage can swing to within 80 mV of either supply rail
when driving light loads and within 0.17 V when driving 150 Ω.
High speed performance is maintained at supply voltages as low
as 2.7 V.
Higher frequency signals require more headroom than the
lower frequencies to maintain distortion performance. Figure 39
illustrates how the rising edge settling time for the amplifier
configured as a unity-gain follower stretches out as the top of a
1 V step input approaches and exceeds the specified input
common-mode voltage limit.
3.6
HEADROOM AND OVERDRIVE RECOVERY
CONSIDERATIONS
VS = 5V
G = +1
RL = 1kΩ
3.4
3.0
2.8
VSTEP = 2V TO 3V
VSTEP = 2.1V TO 3.1V
2.6
VSTEP = 2.2V TO 3.2V
2.4
VSTEP = 2.3V TO 3.3V
2.2
VSTEP = 2.4V TO 3.4V
2.0
1.8
0
10
20
30
40
50
60
70
80
90
100
TIME (ns)
05320-061
The ADA4850-1/ADA4850-2 are designed for use in low
voltage systems. To obtain optimum performance, it is useful to
understand the behavior of the amplifier as input and output
signals approach the amplifier’s headroom limits. The input
common-mode voltage range extends 200 mV below the
negative supply voltage or ground for single-supply operation to
within 2.2 V of the positive supply voltage. Therefore, in a gain
of +3, the ADA4850-1/ADA4850-2 can provide full rail-to-rail
output swing for supply voltage as low as 3.3 V, assuming the
input signal swing is from −VS (or ground) to 1.1 V.
OUTPUT VOLTAGE (V)
3.2
Input
Figure 39. Pulse Response, Input Headroom Limits
Exceeding the headroom limit is not a concern for any inverting
gain on any supply voltage, as long as the reference voltage at
the amplifier’s positive input lies within the amplifier’s input
common-mode range.
The input stage sets the headroom limit for signals when the
amplifier is used in a gain of +1 for signals approaching the
positive rail. For high speed signals, however, there are other
considerations. Figure 38 shows −3 dB bandwidth vs. dc input
voltage for a unity-gain follower. As the common-mode voltage
approaches the positive supply, the bandwidth begins to drop
when within 2 V of +VS. This can manifest itself in increased
distortion or settling time.
2
VCM = 3V
1
VCM = 3.1V
VCM = 3.2V
0
VCM = 3.3V
–3
–4
–5
–6
0.1
VS = 5V
G = +1
RL = 1kΩ
VOUT = 0.1V p-p
1
The ADA4850-1/ADA4850-2 do not exhibit phase reversal, even
for input voltages beyond the voltage supply rails. Going more than
0.6 V beyond the power supplies turns on protection diodes at the
input stage, which greatly increase the current draw of the devices.
Output
For signals approaching the negative supply and inverting gain,
and high positive gain configurations, the headroom limit is the
output stage. The ADA4850-1/ADA4850-2 amplifiers use a
common-emitter output stage. This output stage maximizes the
available output range, limited by the saturation voltage of the
output transistors. The saturation voltage increases with drive
current, due to the output transistor collector resistance.
As the saturation point of the output stage is approached, the
output signal shows increasing amounts of compression and
clipping. As in the input headroom case, higher frequency signals
require a bit more headroom than the lower frequency signals.
–2
Output overload recovery is typically within 40 ns after the
amplifier’s input is brought to a nonoverloading value.
10
100
FREQUENCY (MHz)
Figure 38. Unity-Gain Follower Bandwidth vs.
Frequency for Various Input Common-Mode
1000
05320-096
GAIN (dB)
–1
The recovery time from input voltages 2.2 V or closer to the
positive supply is approximately 50 ns, which is limited by the
settling artifacts caused by transistors in the input stage coming
out of saturation.
Figure 40 shows the output recovery transients for the amplifier
recovering from a saturated output from the top and bottom
supplies to a point at midsupply.
Rev. A | Page 12 of 16
ADA4850-1/ADA4850-2
6.5
The ADA4850-1/ADA4850-2 can operate on bipolar supplies
up to ±5 V. The only restriction is that the voltage between −VS
and the power-down pin must not exceed 6 V. Voltage
differences greater than 6 V can cause permanent damage to the
amplifier. For example, when operating on ±5 V supplies, the
power-down pin must not exceed +1 V.
4.5
3.5
INPUT
2.5 VOLTAGE
EDGES
1.5
0.5
POWER-DOWN PINS
VOUT = –2.5V TO 0V
–0.5
–1.5
0
10
20
30
40
50
60
70
TIME (ns)
Figure 40. Overload Recovery
80
90
100
05320-042
INPUT AND OUTPUT VOLTAGE (V)
OPERATING THE ADA4850-1/ADA4850-2 ON
BIPOLAR SUPPLIES
VS = 5V
G = –1
RL = 1kΩ
VOUT = +2.5V TO 0V
5.5
The ADA4850-1/ADA4850-2 feature an ultralow power-down
mode that lowers the supply current to less than 150 nA. When
a power-down pin is brought to within 0.6 V of the negative
supply, the amplifier is powered down. Table 5 outlines the
power-down pin functionality. To ensure proper operation, the
power-down pins (PD) should not be left floating.
Table 5. Power-Down Pins Functionality
Supply Voltage
Powered Down
Enabled
Rev. A | Page 13 of 16
3 V and 5 V
ADA4850-1
ADA4850-2
0 V to 0.7 V
0 V to 0.6 V
0.8 to +VS
1.7 V to +VS
ADA4850-1/ADA4850-2
OUTLINE DIMENSIONS
3.00
BSC SQ
0.50
0.40
0.30
0.60 MAX
0.45
1
8
PIN 1
INDICATOR
0.90
0.85
0.80
2.75
BSC SQ
TOP
VIEW
1.50
REF
EXPOSED
PAD
0.50
BSC
(BOTTOM VIEW)
1.89
1.74
1.59
4
5
0.25
MIN
0.80 MAX
0.65 TYP
12° MAX
PIN 1
INDICATOR
1.60
1.45
1.30
0.05 MAX
0.02 NOM
SEATING
PLANE
0.30
0.23
0.18
0.20 REF
Figure 41. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD]
3 mm × 3 mm Body, Very Thin, Dual Lead
(CP-8-2)
Dimensions shown in millimeters
3.00
BSC SQ
0.60 MAX
13
12
0.45
PIN 1
INDICATOR
TOP
VIEW
2.75
BSC SQ
0.80 MAX
0.65 TYP
12° MAX
SEATING
PLANE
16
1
PIN 1
INDICATOR
*1.65
1.50 SQ
1.35
EXPOSED
PAD
0.50
BSC
0.90
0.85
0.80
0.50
0.40
0.30
9 (BOTTOM VIEW) 4
8
5
0.25 MIN
1.50 REF
0.05 MAX
0.02 NOM
0.30
0.23
0.18
0.20 REF
*COMPLIANT TO JEDEC STANDARDS MO-220-VEED-2
EXCEPT FOR EXPOSED PAD DIMENSION.
Figure 42. 16-Lead Lead Frame Chip Scale Package [LFCSP_VQ]
3 mm × 3 mm Body, Very Thin Quad
(CP-16-3)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADA4850-1YCPZ-R21
ADA4850-1YCPZ-RL1
ADA4850-1YCPZ-RL71
ADA4850-2YCPZ-R21
ADA4850-2YCPZ-RL1
ADA4850-2YCPZ-RL71
1
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
8-Lead Lead Frame Chip Scale Package (LFCSP_VD)
8-Lead Lead Frame Chip Scale Package (LFCSP_VD)
8-Lead Lead Frame Chip Scale Package (LFCSP_VD)
16-Lead Lead Frame Chip Scale Package (LFCSP_VQ)
16-Lead Lead Frame Chip Scale Package (LFCSP_VQ)
16-Lead Lead Frame Chip Scale Package (LFCSP_VQ)
Z = Pb-free part.
Rev. A | Page 14 of 16
Package Outline
CP-8-2
CP-8-2
CP-8-2
CP-16-3
CP-16-3
CP-16-3
Branding
HWB
HWB
HWB
HTB
HTB
HTB
ADA4850-1/ADA4850-2
NOTES
Rev. A | Page 15 of 16
ADA4850-1/ADA4850-2
NOTES
©2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05320–0−4/05(A)
Rev. A | Page 16 of 16