Analog Devices AD8336 Service Manual

General-Purpose, −55°C to +125°C,

VGA

FEATURES

Low noise

Voltage noise: 3 nV/√Hz

Current noise: 3 pA/√Hz Small signal BW: 115 MHz Large signal BW: 2 V p-p = 80 MHz Slew rate: 550 V/µs, 2 V p-p Gain ranges (specified)

−14 dB to +46 dB,

0 dB to 60 dB Gain scaling: 50 dB/V DC-coupled Single-ended input and output Supplies: ±3 V to ±12 V Temperature Range: −55°C to +125°C Power

150 mW @ ±3 V, −55°C < T < +125°C

84 mW @ ±3 V, PWRA = 3 V

APPLICATIONS

Industrial process controls High performance AGC systems I/Q signal processing Video Industrial and medical ultrasound Radar receivers

Wide Bandwidth, DC-Coupled VGA

AD8336

FUNCTIONAL BLOCK DIAGRAM

IPRAO

98

ATTENUATOR –60dB TO 0dB

BIAS

13 3 11 12

VCOMVPOS GPOS

Figure 1.

34d BPrA

GAIN CONTROL

INTERFACE

GNEG

1

VOUT

06228-001

INPP

INPN

PWR A

AD8336

4

+

–

5

2

10

VNEG

GENERAL DESCRIPTION

The AD8336 is a low noise, single-ended, linear-in-dB, generalpurpose variable gain amplifier, usable over a large range of supply voltages. It features an uncommitted preamplifier (preamp) with a usable gain range of 6 dB to 26 dB established by external resistors in the classical manner. The VGA gain range is 0 dB to 60 dB, and its absolute gain limits are −26 dB to +34 dB. When the preamplifier gain is adjusted for 12 dB, the combined 3 dB bandwidth of the preamp and VGA is 100 MHz, and the amplifier is fully usable to 80 MHz. With ±5 V supplies, the maximum output swing is 2 V p-p.

Thanks to its X-Amp® architecture, excellent bandwidth uniformity is maintained across the entire gain range of the VGA. Intended for a broad spectrum of applications, the differential gain control interface provides precise linear-in-dB gain scaling of 50 dB/V over the temperature span of −55°C to +125 °C. The differential gain control is easy to interface with a variety of external circuits within the common-mode voltage limits of the AD8336.

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og 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.

The large supply voltage range makes the AD8336 particularly suited for industrial medical applications and for video circuits. Dual-supply operation enables bipolar input signals, such as those generated by photodiodes or photomultiplier tubes.

The fully independent voltage feedback preamp allows both inverting and noninverting gain topologies, making it a fully bipolar VGA. The AD8336 can be used within the specified gain range of −14 dB to +60 dB by selecting a preamp gain between 6 dB and 26 dB and choosing appropriate feedback resistors. For the nominal preamp gain of 4×, the overall gain range is −14 dB to +46 dB.

In critical applications, the quiescent power can be reduced by about half by using the power adjust pin, PWRA. This is especially useful when operating with high supply voltages of up to ±12 V, or at high temperatures.

The operating temperature range is −55°C to +125°C. The AD8336 is available in a 16-lead LFCSP (4 mm × 4 mm).

www.analog.com

AD8336

REVISION HISTORY

10/06—Revision 0: Initial Version

Rev. 0 | Page 2 of 28

AD8336

SPECIFICATIONS

VS = ±5 V, T = 25°C, gain range = −14 dB to +46 dB, preamp gain = 4×, f = 1 MHz, CL = 5 pF, RL = 500 Ω, PWRA = GND, unless otherwise specified.

Table 1.

Parameter Conditions Min Typ Max Unit

PREAMPLIFIER

−3 dB Small Signal Bandwidth V

−3 dB Large Signal Bandwidth V Bias Current, Either Input 725 nA Differential Offset Voltage ±600 μV Input Resistance 900 kΩ Input Capacitance 3 pF

PREAMPLIFIER + VGA

–3 dB Small Signal Bandwidth V V V V

–3 dB Large Signal Bandwidth V V V V Slew Rate V Short-Circuit Preamp Input Voltage

Noise Spectral Density Input Current Noise Spectral Density 3.0 pA/√Hz Output Referred Noise V V V V V V

DYNAMIC PERFORMANCE

Harmonic Distortion V

HD2 f = 1 MHz –58 dBc

HD3 f = 1 MHz –68 dBc

HD2 f = 10 MHz –60 dBc

HD3 f = 10 MHz –60 dBc Input 1 dB Compression Point V V Two-Tone Intermodulation V

Distortion (IMD3) V V V Output Third-Order Intercept V V V V Overdrive Recovery V Group Delay Variation 1 MHz < f < 10 MHz, full gain range ±1 ns

PrA Gain = 20 × 1 MHz < f < 10 MHz, full gain range ±3 ns

= 10 mV p-p 150 MHz

OUT

= 2 V p-p 85 MHz

OUT

= 10 mV p-p 115 MHz

OUT

= 10 mV p-p, PWRA = 5 V 40 MHz

OUT

= 10 mV p-p, PrA gain = 20× 20 MHz

OUT

= 10 mV p-p, PrA gain = –3× 125 MHz

OUT

= 2 V p-p 80 MHz

OUT

= 2 V p-p, PWRA = 5 V 30 MHz

OUT

= 2 V p-p, PrA gain = 20× 20 MHz

OUT

= 2 V p-p, PrA gain = –3× 100 MHz

OUT

= 2 V p-p 550 V/µs

OUT

±3 V ≤ V

≤ ±12 V

S

= 0.7 V, PrA gain = 4× 600 nV/√Hz

GAIN

= –0.7 V, PrA gain = 4× 190 nV/√Hz

GAIN

= 0.7 V, PrA gain = 20× 2500 nV/√Hz

GAIN

= –0.7 V, PrA gain = 20× 200 nV/√Hz

GAIN

= 0.7 V, –55°C ≤ T ≤ +125°C 700 nV/√Hz

GAIN

= –0.7 V, –55°C ≤ T ≤ +125°C 250 nV/√Hz

GAIN

= 0 V, V

GAIN

= –0.7 V 11 dBm

GAIN

= +0.7 V –23 dBm

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0 V, V

GAIN

= 0.7 V, VIN = 100 mV p-p to 5 mV p-p 50 ns

GAIN

= 1 V p-p

OUT

= 1 V p-p, f1 = 0.95 MHz, f2 = 1.05 MHz –71 dBc

OUT

= 1 V p-p, f1 = 9.95 MHz, f2 = 10.05 MHz –69 dBc

OUT

= 2 V p-p, f1 = 0.95 MHz, f2 = 1.05 MHz –60 dBc

OUT

= 2 V p-p, f1 = 9.95 MHz, f2 = 10.05 MHz –58 dBc

OUT

= 1 V p-p, f = 1 MHz 34 dBm

OUT

= 1 V p-p, f = 10 MHz 32 dBm

OUT

= 2 V p-p, f = 1 MHz 34 dBm

OUT

= 2 V p-p, f = 10 MHz 33 dBm

OUT

3.0 nV/√Hz

1

Rev. 0 | Page 3 of 28

AD8336

Parameter Conditions Min Typ Max Unit

ABSOLUTE GAIN ERROR

−0.6 V < V

−0.5 V < V

0.5 V < V

0.6 V < V GAIN CONTROL INTERFACE

Gain Scaling Factor 48 49.9 52 dB/V Intercept Preamp + VGA 16.4 dB

VGA Only 4.5 dB Gain Range 58 60 62 dB Input Voltage (V Input Current 1 μA Input Capacitance pF Response Time 60 dB gain change 300 ns

OUTPUT PERFORMANCE

Output Impedance, DC to 10 MHz ±3 V ≤ VS ≤ ±12 V 2.5 Ω Output Signal Swing RL ≥ 500 Ω (for |V R Output Current Linear operation − minimum discernable distortion 20 mA Short-Circuit Current VS = ±3 V +123/−72 mA V V Output Offset Voltage V ±3 V ≤ VS ≤ ±12 V −200 mV

−55°C ≤ T ≤ +125°C −200 mV

PWRA Pin

Normal Power (Logic Low) VS = ±3 V 0.7 V Low Power (Logic High) VS = ±3 V 1.5 V Normal Power (Logic Low) VS = ±5 V 1.2 V Low Power (Logic High) VS = ±5 V 2.0 V Normal Power (Logic Low) VS = ±12 V 3.2 V Low Power (Logic High) VS = ±12 V 4.0 V

POWER SUPPLY

Supply Voltage Operating Range ±3 ±12 V Quiescent Current

VS = ±3 V 22 25 30

−55°C ≤ T ≤ +125°C 23 to 31 mA

PWRA = 3 V 10 14 18

VS = ±5 V 22 26 30

−55°C ≤ T ≤ +125°C 23 to 31 mA

PWRA = 5 V 10 14 18

VS = ±12 V 23 28 31

−55°C ≤ T ≤ +125°C 24 to 33 mA PWRA = 5 V 16

2

) Range No foldover −V

GAIN

−0.7 V < V

≥ 1 kΩ (for |V

L

= ±5 V +123/−72 mA

S

= ±12 V +72/−73 mA

S

= 0.7 V, gain = 200× −250 −125 150 mV

GAIN

< −0.6 V 0 1 to 5 6 dB

GAIN

< −0.5 V 0 0.5 to1.5 3 dB

GAIN

< 0.5 V −1.25 ±0.2 +1.25 dB

GAIN

< 0.5 V, ±3 V ≤ VS ≤ ±12 V ±0.5 1.25 dB

GAIN

< 0.5 V, −55 °C ≤ T ≤ +125 °C ±0.5 dB

GAIN

< 0.5 V, PrA gain = −3× ±0.5 dB

GAIN

< 0.6 V −4.0 −1.5 to −3.0 0 dB

GAIN

< 0.7 V −9.0 −1 to −5 0 dB

GAIN

| ≤ ±5V); RL ≥ 1 kΩ above that |V

SUPPLY

| = ±12V) |V

SUPPLY

+V

S

SUPPLY

S

| − 1.5 V | − 2.25 V

V

Rev. 0 | Page 4 of 28

AD8336

Parameter Conditions Min Typ Max Unit

Power Dissipation VS = ±3 V 150 mW V V PSRR V

1

All dBm values are calculated with 50 Ω reference, unless otherwise noted.

2

Conformance to theoretical gain expression (see the S section). etting the Gain

= ±5 V 260 mW

S

= ±12 V 672 mW

S

= 0.7 V, f = 1 MHz −40 dB

GAIN

Rev. 0 | Page 5 of 28

AD8336

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Supply Voltage (VPOS, VNEG) Input Voltage (INPP, INPN) VPOS, VNEG Gain Voltage (GPOS, GNEG) VPOS, VNEG PWRA 5 V, GND Power Dissipation

VS ≤ ±5 V 0.43 W ±5 V < VS ≤ ±12 V 1.12 W

Operating Temperature Range

±3 V < VS ≤ ±10 V –55°C to +125°C ±10 V < VS ≤ ±12 V –55°C to +85°C

Storage Temperature Range –65°C to +150°C Lead Temperature (Soldering 60 sec) 300°C Thermal Data (4-layer JEDEC board, no air

flow, exposed pad soldered to PC board) θ

JA

θ

JB

θ

JC

Ψ

JT

Ψ

JB

±15 V

58.2°C/W

35.9°C/W

9.2°C/W

1.1°C/W

34.5°C/W

Stresses above those listed under the 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.

ESD CAUTION

Rev. 0 | Page 6 of 28

AD8336

A

V

PIN CONFIGURATION AND FUNCTIONAL DESCRIPTIONS

VPOS

NCNCNC

14 131516

1

VOUT

PWR

COM INPP

NC = NO CONNECT

PIN 1 INDICATOR

2

AD8336

3

TOP VIEW

(Not to Scale)

4

INPN

Figure 2. 16-Lead LFCSP Pin Configuration

Table 3. Pin Function Descriptions

Pin No. Mnemonic Function

1 VOUT Output Voltage. 2 PWRA Power Control. Normal power when grounded; power reduced by half if V 3 VCOM Common-Mode Voltage. Normally GND when using a dual supply. 4 INPP Positive Input to Preamp. 5 INPN Negative Input to Preamp. 6 NC No Connect. 7 NC No Connect. 8 PRAO Preamp Output. 9 VGAI VGA Input. 10 VNEG Negative Supply. 11 GPOS Positive Gain Control Input. 12 GNEG Negative Gain Control Input. 13 VPOS Positive Supply. 14 NC No Connect. 15 NC No Connect. 16 NC No Connect.

NC

12

GNEG

11

GPOS

10

VNEG

9

VGAI

8765

PRAO

06228-002

is pulled high.

PWRA

Rev. 0 | Page 7 of 28

AD8336

R

TYPICAL PERFORMANCE CHARACTERISTICS

VS = ±5 V, T = 25°C, gain range = −14 dB to +46 dB, PrA gain = +4×, f = 1 MHz, CL = 5 pF, RL = 500 Ω, PWRA = GND, unless otherwise specified.

(dB)

–0.5

GAIN ERRO

–1.0

–1.5

2.0

1.5

1.0

0.5

T = +125°C T = +25°C T = –55°C

0

GAIN (dB)

–10

50

40

30

20

10

0

T = +125°C T = +25°C T = –55°C

–20

–600 –400 –200 200 400 600 800

–800

Figure 3. Gain vs. V

50

VS = ±12V V

= ±5V

S

V

= ±3V

S

40

30

20

10

GAIN (dB)

0

–10

–20

–600 –400 –200 200 400 600 800

Figure 4. Gain vs. V

70

60

50

40

30

20

GAIN (dB)

10

0

–10

–20

–600 –400 –200 200 400 600 800

Figure 5 Gain vs. V

0

(mV)

V

GAIN

for Three Values of Temperature (T)

GAIN

0–800

V

(mV)

GAIN

for Three Values of Supply Voltage (VS)

GAIN

PREAMP GAIN = 4×PREAMP GAIN = 20×

0–800

V

(mV)

GAIN

for Preamp Gains of 4× and 20×

GAIN

–2.0

06228-003

–600 –400 –200 200 400 600 800

Figure 6. Gain Error vs. V

2.0

1.5

1.0

0.5

0

–0.5

GAIN ERROR (dB)

–1.0

–1.5

–2.0

6228-004

Figure 7. Gain Error vs. V

–0.5

GAIN ERROR (dB)

–1.0

–1.5

–2.0

6228-005

–600 –400 –200 200 400 600 800

GAIN

2.0

1.5

1.0

0.5

0

–600 –400 –200 200 400 600 800

Figure 8. Gain Error vs. V

0–800

V

(mV)

GAIN

for Three Values of Temperature (T)

GAIN

VS = ±12V V

= ±5V

S

VS = ±3V

0–800

(mV)

V

GAIN

for Three Values of Supply Voltage (VS)

PREAMP GAIN = 20× PREAMP GAIN = 4×

0–800

(mV)

V

GAIN

for Preamp Gains of 4× and 20×

GAIN

06228-006

06228-007

06228-008

Rev. 0 | Page 8 of 28

AD8336

2.0

1.5

1.0

PREAMP GAIN = 4×, f = 1MHz PREAM P GAIN = 4×, f = 10MH z PREAM P GAIN = 20×, f = 1MHz PREAM P GAIN = 20×, f = 10MHz

50

40

60 UNITS V

GAIN

V

GAIN

= –0.3V = +0.3V

0.5

0

–0.5

GAIN ERROR (dB)

–1.0

–1.5

–2.0

–600 –400 –200 200 400 600 800

Figure 9. Gain Error vs. V

0–800

V

(mV)

GAIN

at 1 MHz and 10 MHz and

GAIN

for Preamp Gains of 4× and 20×

2.0

1.5

1.0

0.5

0

–0.5

GAIN ERROR (dB)

–1.0

–1.5

–2.0

–600 –400 –200 200 400 600 800

Figure 10. Gain Error vs. V

PREAMP GAIN = –3×, f = 1MHz PREAMP GAIN = –3×, f = 10MHz PREAMP GAIN = –19×, f = 1MHz PREAMP GAIN = –19×, f = 10MHz

0–800

(mV)

V

GAIN

at 1 MHz and 10 MHz and

GAIN

for Inverting Preamp Gains of −3× and −19×

50

45

40

35

GAIN (dB)

–5

–10

–15

VS = ±12V

= ±5V

V

S

= ±3V

V

S

0

–15 –10 –5 0 5 10

COMMON-MODE VOLTAGE OF V

GAIN

30

20

% OF UNITS

10

0

–0.12

06228-009

–0.08

0

–0.04

GAIN ERROR (dB)

0.16

0.12

0.08

0.04

06228-012

Figure 12. Gain Error Histogram

50

60 U NITS

–0.3V ≤ V

40

30

20

% OF UNITS

10

0

6228-010

49.6 49.7 49.8 49.9 50.0 50.1 50.2

≤ 0.3V

GAIN

GAIN SCALING (dB/V)

06228-013

Figure 13. Gain Scaling Factor Histogram

20

0

–20

–40

–60

–80

–100

–120

–140

OFFSET VOLTAGE (mV)

–160

T = +125°C

–180

T = +85°C T = +25°C

15

06228-011

–200

–220

T = –40°C T = –55°C

V

GAIN

(V)

0.2000.60.4–0.8 –0.6 –0.2–0.4

.8

06228-014

Figure 11. Common-Mode Voltage at Pin V

GAIN

vs. V

GAIN

Rev. 0 | Page 9 of 28

Figure 14. Output Offset Voltage vs. V

Various Values of Temperature (T)

GAIN

for

Analog Devices AD8336 Service Manual

FEATURES

APPLICATIONS

FUNCTIONAL BLOCK DIAGRAM

GENERAL DESCRIPTION

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

ESD CAUTION

PIN CONFIGURATION AND FUNCTIONAL DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS