AD ADA4850-1YCPZ-RL7 High speed, rail-to-rail output op amps with ultralow power-down Datasheet

High Speed, Rail-to-Rail Output
Op Amps with Ultralow Power-Down
ADA4850-1/ADA4850-2
PIN CONFIGURATIONS
Ultralow power-down current: 150 nA/amplifier maximum
Low quiescent current: 2.4 mA/amplifier
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
13 PD2
14 PD1
15 NC
16 NC
Figure 1. 8-Lead, 3 mm × 3 mm LFCSP
ADA4850-2
12 +VS
VOUT1 1
APPLICATIONS
–IN1 2
11 VOUT2
+IN1 3
10 –IN2
–VS 4
+IN2
05320-043
NC 8
NC 6
NC 7
9
NC 5
Portable multimedia players
Video cameras
Digital still cameras
Consumer video
Clock buffers
NC = NO CONNECT
Figure 2. 16-Lead, 3 mm × 3 mm LFCSP
GENERAL DESCRIPTION
1
–1
–2
–3
–4
G = +1
VS = 5V
RL = 1kΩ
VOUT = 0.1V p-p
–5
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.
With its combination of low price, excellent differential gain
(0.12%), differential phase (0.09°), and 0.1 dB flatness out to
14 MHz, these amplifiers are ideal for video applications.
0
–6
1
10
100
FREQUENCY (MHz)
1000
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.
2
CLOSED-LOOP GAIN (dB)
The ADA4850-1/ADA4850-21 are low price, high speed, voltage
feedbacks rail-to-rail output op amps with ultralow powerdown. 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 general-purpose, high speed
applications.
Figure 3. Small Signal Frequency Response
1
Patents pending.
The ADA4850-1/ADA4850-2 are designed to work in the
extended temperature range of −40°C to +125°C.
Rev. B
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 ©2005–2007 Analog Devices, Inc. All rights reserved.
ADA4850-1/ADA4850-2
TABLE OF CONTENTS
Features .............................................................................................. 1
ESD Caution...................................................................................5
Applications....................................................................................... 1
Typical Performance Characteristics ..............................................6
Pin Configurations ........................................................................... 1
Circuit Description......................................................................... 12
General Description ......................................................................... 1
Headroom and Overdrive Recovery Considerations ............ 12
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Operating the ADA4850-1/ADA4850-2 on Bipolar
Supplies........................................................................................ 13
Specifications with +3 V Supply................................................. 3
Power-Down Pins....................................................................... 13
Specifications with +5 V Supply................................................. 4
Outline Dimensions ....................................................................... 14
Absolute Maximum Ratings............................................................ 5
Ordering Guide .......................................................................... 14
Thermal Resistance ...................................................................... 5
REVISION HISTORY
12/07—Rev. A to Rev. B
Changes to Applications .................................................................. 1
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 14
4/05—Rev. 0 to Rev. A
Added ADA4850-1.............................................................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. B | Page 2 of 16
ADA4850-1/ADA4850-2
SPECIFICATIONS
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 Range 1
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. B | 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 Range 1
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. B | 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.
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
surface-mount packages.
⎞ 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.
Unit
°C/W
°C/W
2.5
Maximum Power Dissipation
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.
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
θJA
91
80
⎛V V
PD = (VS × I S ) + ⎜⎜ S × OUT
RL
⎝ 2
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.
Table 4.
Package Type
16-Lead LFCSP
8-Lead LFCSP
PD = Quiescent Power + (Total Drive Power − Load Power)
MAXIMUM POWER DISSIPATION (W)
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
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).
Figure 4. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
ESD CAUTION
Rev. B | 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
2
G = +2
–2
–3
G = +10
–4
6pF
G = +1
VS = 5V
RL = 1kΩ
VOUT = 0.1V p-p
3
CLOSED-LOOP GAIN (dB)
1
0
1pF
–1
0pF
–2
–3
–4
–5
–6
1
10
100
FREQUENCY (MHz)
1
05320-044
–6
Figure 5. Small Signal Frequency Response for Various Gains
100
6.2
1
RL = 150Ω
–1
5.9
GAIN (dB)
6.0
RL = 1kΩ
–2
VS = 5V
G = +2
RL = 150Ω
6.1
0
–3
VS = 5V, VOUT = 2V p-p
5.8
VS = 5V, VOUT = 1.4V p-p
VS = 3V, VOUT = 0.5V p-p
5.7
–4
VS = 5V, VOUT = 0.1V p-p
5.6
VS = 5V
G = +1
VOUT = 0.1V p-p
–6
1
10
100
1000
FREQUENCY (MHz)
5.4
100k
1M
10M
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
–5
100M
FREQUENCY (Hz)
–1
RL = 150Ω
–2
RL = 1kΩ
–3
–4
–5
–6
10
100
1000
FREQUENCY (MHz)
05320-046
–7
–6
1
05320-047
5.5
05320-045
–5
CLOSED-LOOP GAIN (dB)
300
Figure 8. Small Signal Frequency Response for Various Capacitor Loads
2
CLOSED-LOOP GAIN (dB)
10
FREQUENCY (MHz)
05320-007
–5
1
10
100
1000
FREQUENCY (MHz)
Figure 10. Large Frequency Response for Various Loads
Figure 7. Small Signal Frequency Response for Various Supplies
Rev. B | Page 6 of 16
05320-048
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
10
1
100
0
05320-057
–5
1000
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
10k
3
VS = 5V
G = +1
RL = 1kΩ
VOUT = 0.1V p-p
+125°C
1
1k
SUPPLY CURRENT (μA)
2
CLOSED-LOOP GAIN (dB)
NEGATIVE SLEW RATE
1
SLEW RATE (V/μs)
CLOSED-LOOP GAIN (dB)
2
+125°C
+85°C
0
–1
+25°C
–2
–40°C
VS = 3V, 5V, ADA4850-2
100
VS = 3V, 5V, ADA4850-1 ENABLE
10
VS = 3V, 5V, ADA4850-1 POWER DOWN
–3
1
10
1
100
0.1
05320-098
–5
1000
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. B | 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
10
100
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
10
100
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
2.875
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
G = +2
RL = 1kΩ
VS = 5V
0.55
0.50
0.45
0.40
0.875
G = +1
RL = 1kΩ
2.750
0.750
2.625
0.625
2.500
0.500
2.375
VS = 5V
2.250
0.375
0.250
0
50
100
150
200
TIME (ns)
05320-019
VS = 3V
0.35
2.125
0
50
100
150
0.125
200
TIME (ns)
Figure 22. Large Signal Transient Response for Various Supplies
Figure 19. Small Signal Transient Response for Various Supplies
Rev. B | 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
100
200
300
400
500
600
700
800
900
1000
TIME (ns)
1
10
05320-058
0
100
10k
100k
1M
10M
100M
1G
3
4
FREQUENCY (Hz)
Figure 24. Input Overdrive Recovery
Figure 27. Current Noise vs. Frequency
350
3.5
3.0
OUTPUT
G = +5
VS = 3V
RL = 150Ω
f = 1MHz
300
2.5
VS = 5V
N = 1720
x = 450μV
σ = 750μV
250
COUNT
2.0
5 × INPUT
1.5
200
150
1.0
100
0.5
50
–0.5
0
100
200
300
400
500
600
700
800
TIME (ns)
900
1000
Figure 25. Output Overdrive Recovery
0
–4
–3
–2
–1
0
1
2
VOFFSET (mV)
Figure 28. Input Offset Voltage Distribution
Rev. B | Page 9 of 16
05320-065
0
05320-060
INPUT AND OUTPUT VOLTAGE (V)
1k
05320-095
0
–0.5
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
95
0.6
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)
80
–VS – VOUT
75
70
65
–40
–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)
4.9
–30
4.8
VS = 3V
VS = 5V
SUPPLY CURRENT (mA)
–34
–36
–38
–40
–42
VS = 5V
05320-091
–44
–25
–10
5
20
35
50
65
80
95
110
125
4.7
4.6
VS = 3V
4.5
4.4
4.3
4.2
–40
05320-090
–32
–46
–40
+VS – VOUT
85
05320-064
0
0
VS = 5V
RL = 1kΩ
OUTPUT SATURATION VOLTAGE (mV)
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)
TEMPERATURE (°C)
Figure 31. Power-Down Bias Current vs. Temperature for Various Supplies
Rev. B | 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
CHANNEL 1
–60
–70
CHANNEL 2
–80
–90
–100
–110
–110
100
–120
1k
1k
10k
100k
1M
10M
05320-094
–100
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
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 37. Common-Mode Rejection (CMR) vs. Frequency
Figure 35. Power Supply Rejection (PSR) vs. Frequency
–0.1
–40
10k
125
TEMPERATURE (°C)
Figure 36. Input Offset Voltage vs. Temperature for Various Supplies
Rev. B | 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
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
VCM = 3.1V
VCM = 3.2V
0
VCM = 3.3V
–3
–5
–6
0.1
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
VSTEP = 2.4V TO 3.4V
2.0
1.8
0
10
20
30
40
50
60
70
80
90
100
TIME (ns)
Figure 39. Pulse Response, Input Headroom Limits
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.
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
–4
2.8
2.2
VS = 5V
G = +1
RL = 1kΩ
VOUT = 0.1V p-p
1
Output overload recovery is typically within 40 ns after the
amplifier’s input is brought to a nonoverloading value.
10
100
FREQUENCY (MHz)
1000
05320-096
GAIN (dB)
–1
3.0
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 railto-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
1
VS = 5V
G = +1
RL = 1kΩ
3.4
Figure 38. Unity-Gain Follower Bandwidth vs.
Frequency for Various Input Common-Mode
Rev. B | Page 12 of 16
ADA4850-1/ADA4850-2
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.
6.5
4.5
3.5
INPUT
2.5 VOLTAGE
EDGES
1.5
0.5
VOUT = –2.5V TO 0V
–0.5
–1.5
0
10
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.
POWER-DOWN PINS
20
30
40
50
60
70
TIME (ns)
80
90
100
05320-042
INPUT AND OUTPUT VOLTAGE (V)
VS = 5V
G = –1
RL = 1kΩ
VOUT = +2.5V TO 0V
5.5
OPERATING THE ADA4850-1/ADA4850-2 ON
BIPOLAR SUPPLIES
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 pins functionality. To ensure proper operation, the
power-down pins (PD1, PD2) should not be left floating.
Table 5. Power-Down Pins Functionality
Figure 40. Overload Recovery
Supply Voltage
Power Down
Enabled
Rev. B | Page 13 of 16
3 V and 5 V
ADA4850-1
0 V to 0.7 V
0.8 to +VS
ADA4850-2
0 V to 0.6 V
1.7 V to +VS
ADA4850-1/ADA4850-2
OUTLINE DIMENSIONS
3.25
3.00 SQ
2.75
0.60 MAX
5
2.95
2.75 SQ
2.55
TOP
VIEW
PIN 1
INDICATOR
8
12° MAX
1.60
1.45
1.30
EXPOSED
PAD
(BOTTOM VIEW)
4
1
0.50
0.40
0.30
0.70 MAX
0.65 TYP
0.90 MAX
0.85 NOM
0.50
BSC
0.60 MAX
1.89
1.74
1.59
PIN 1
INDICATOR
0.05 MAX
0.01 NOM
0.20 REF
061507-B
0.30
0.23
0.18
SEATING
PLANE
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-R2 1
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 = RoHS Compliant Part.
Rev. B | Page 14 of 16
Package Option
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. B | Page 15 of 16
ADA4850-1/ADA4850-2
NOTES
©2005–2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05320-0-12/07(B)
Rev. B | Page 16 of 16