®
®
SHM-12
Ultra-Fast, 12-Bit Linear
Monolithic Sample-Hold Amplifiers
IN N O VA T IO N a n d E X C E L L E N C E
FEATURES
•
Fast acquisition time:
10ns to ±0.1%
15ns to ±0.024%
20ns to ±0.012%
•
±0.006% Nonlinearity
•
65µVrms output noise
•
120MHz small signal bandwidth
•
55MHz full power bandwidth
•
–80dB feedthrough
•
1ps Aperture jitter
•
250mW power dissipation
•
Low cost
INPUT/OUTPUT CONNECTIONS
(CLCC and SOIC-20 Packages)
PIN
1
2
3
4
5
6
7
8
9
10
FUNCTION
–5V SUPPLY
–5V SUPPLY
NOT CONNECTED
ANALOG INPUT
–5V SUPPLY
DO NOT CONNECT
–5V SUPPLY
DO NOT CONNECT
–5V SUPPLY
–5V SUPPLY
PIN
20
19
18
17
16
15
14
13
12
11
FUNCTION
+5V SUPPLY
SAMPLE/HOLD
SAMPLE/HOLD
+5V SUPPLY
GROUND
EXT. CAPACITOR
GROUND
+5V SUPPLY
+5V SUPPLY
ANALOG OUTPUT
GENERAL DESCRIPTION
The SHM-12 is an extremely high-speed and accurate
monolithic sample-and-hold amplifier designed for fast data
acquisition applications. The SHM-12 is accurate (±1LSB at 12
bits over the full military temperature range) and is very fast
(10ns and 15ns acquisition times to accuracies of 10 and 12-
bits, respectively). With this high performance and a full power
bandwidth of 55MHz, the SHM-12 is an ideal device for driving
flash and high-resolution subranging A/D converters.
A careful design optimizes the device for accuracy and speed
over the full military temperature range. The droop rate is a low
±0.5mV/µs. The 30mA output current and guaranteed
specifications for a 100Ω load provide high drive capability.
Operating from ±5V supplies, the SHM-12 consumes only
250mW of power.
The SHM-12 is built using a fast complementary bipolar
process. The device is available in both military and industrial
temperature ranges. The SHM-12 is packaged in a 20-pin
plastic SOIC or ceramic LCC.
–5V SUPPLY
1, 2, 5, 7, 9, 10
EXTERNAL HOLD
CAPACITOR
15
+5V SUPPLY
12, 13, 17, 20
ANALOG INPUT
4
+1
C
H
15pF
+1
11
ANALOG
OUTPUT
3
NOT CONNECTED
SAMPLE/HOLD
SAMPLE/HOLD
18
19
SWITCH
DRIVE
6, 8
DO NOT
CONNECT
14, 16
GROUND
Figure 1. SHM-12 Functional Block Diagram
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.)
•
Tel: (508) 339-3000 Fax: (508) 339-6356
•
For immediate assistance (800) 233-2765
®
®
SHM-12
ABSOLUTE MAXIMUM RATINGS
PARAMETERS
+5V Supply
–5V Supply
Analog Input
LIMITS
UNITS
Volts
Volts
Volts
Volts
mA
Volts
°C
°C
0 to +6
0 to –6
+5V Supply –1
–5V Supply +1
Continuous Output Current
±50
Digital Inputs
<Supply Voltages
Junction Temperature
+175
Lead Temperature
(10 seconds)
+300
Output shorted to any supply will cause permanent damage.
PERFORMANCE (Cont.)
Acquisition Time
(±0.1%, ±1V)
–40 to +85°C
–55 to +125°C
Hold Mode Settling
(±0.012%)
–40 to +85°C
–55 to +125°C
Hold Mode Settling
(±0.024%)
–40 to +85°C
–55 to +125°C
Hold Mode Settling
(±0.05%)
–40 to +85°C
–55 to +125°C
Hold Mode Settling
(±0.1%)
–40 to +85°C
–55 to +125°C
Slew Rate
Full Power Bandwidth
(±1V)
Small Signal Bandwidth
Output Noise, Hold Mode
Feedthrough
(2V Step)
Droop Rate
+25°C
–40 to +85°C
–55 to +125°C
POWER SUPPLY REQUIREMENTS
Power Supply Range
+5V Supply
–5V Supply
Power Supply Current
+5V Supply
–5V Supply
Power Dissipation
Power Supply Rejection Ratio
ENVIRONMENTAL
—
—
—
—
—
—
—
—
—
+0.98
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
±0.006
—
—
±12
—
—
±3
—
—
+0.995
—
—
2
2
1
1
–75
–62
—
—
20
30
15
25
12
15
—
±0.024
±0.024
—
±20
±30
—
±20
±20
—
±20
±30
—
—
—
—
—
—
–56
–54
—
—
30
40
25
30
%
%
%
mV
mV
mV
mV
mV
mV
V/V
ppm/°C
ppm/°C
ns
ns
ps rms
ps rms
dB
dB
dB
dB
ns
ns
ns
ns
ns
ns
Operating Temp. Range, Case
SHM-12S, SHM-12L
SHM-12LM
Storage Temperature Range
Package Type
SHM-12S
SHM-12L, SHM-12LM
Footnotes:
•
Short circuit protection at ±50mA.
–40
–55
–65
—
—
—
+85
+125
+150
°C
°C
°C
+4.5
–5.5
+17
–17
170
40
+5
–5
+25
–25
250
60
+5.5
–4.5
+30
–30
300
—
Volts
Volts
mA
mA
mW
dB
MIN.
—
—
—
—
—
—
—
—
—
—
±220
35
50
—
—
—
—
—
TYP.
10
10
10
10
7
7
6
6
5
5
±350
55
120
65
–80
±0.5
±2
±2.5
MAX. UNITS
20
20
—
—
18
18
15
15
12
12
—
—
—
—
—
±1.5
±5
±10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
V/µs
MHz
MHz
µVrms
dB
mV/µs
mV/µs
mV/µs
FUNCTIONAL SPECIFICATIONS
(Apply over the operating temperature range using a 100Ω resistive load, 10pF
capacitive load, ECL digital input levels, a 47pF external hold capacitor, and ±5V
nominal supplies, unless otherwise specified.)
INPUTS
Input Voltage Range
Input Impedance
Digitals Inputs
(Balanced ECL)
Logic Levels
Logic 1
Logic 0
Logic Loading
Logic 1
Logic 0
OUTPUTS
Output Voltage Range
Output Current
•
Output Impedance
(dc)
Stable Capacitive Load
PERFORMANCE
Nonlinearity
(±1V)
+25°C
–40 to +85°C
–55 to +125°C
Sample Mode Offset
+25°C
–40 to +85°C
–55 to +125°C
Pedestal
+25°C
–40 to +85°C
–55 to +125°C
Gain,
+25°C
Gain Drift
(±1V)
–40 to +85°C
–55 to +125°C
Aperture Delay
–40 to +85°C
–55 to +125°C
Aperture Jitter
–40 to +85°C
–55 to +125°C
Harmonic Distortion
(±1V)
dc to 1MHz
dc to 10MHz
+25°C
–40 to +85°C
–55 to +125°C
Acquisition Time
(±0.012%, ±1V)
–40 to +85°C
–55 to +125°C
Acquisition Time
(±0.024%, ±1V)
–40 to +85°C
–55 to +125°C
Acquisition Time
(±0.05%, ±1V)
–40 to +85°C
–55 to +125°C
–1.5
± 30
—
—
—
—
0.3
—
+1.5
—
1
50
Volts
mA
Ω
pF
MIN.
–1.5
0.3
–1.5
–2.5
—
—
TYP.
—
1
—
—
+10
–30
MAX. UNITS
+1.5
—
+1.8
+0.8
+50
–150
Volts
MΩ
Volts
Volts
µA
µA
20-Pin plastic SOIC
20-Pin ceramic LCC
TECHNICAL NOTES
The SHM-12 employs an open loop architecture to achieve its
superior high-speed characteristics. The first stage buffer
amplifier incorporates the sample-and-hold switch. This allows
for a fast acquisition time which is not limited by slew current
like the traditional Schottky diode bridge switch. The output
amplifier uses a closed loop voltage feedback design which
provides a low (0.3Ω, typical) output impedance. Gain and
linearity are not affected by heavy loads.
The design has been optimized to achieve the high accuracy
associated with fast transient responses over the military tem-
perature range. During the track-to-hold transient, the integral
nonlinearity is not affected and the pedestal remains constant
over the full ±1.5V input range.
An innovative circuit design ensures an extremely low droop rate.
An external hold capacitor can be added to the 15pF internal
hold capacitor to obtain a lower droop rate (the droop rate is pro-
portional to the inverse of the total hold capacitor value) without
increasing transient response times by more than a few ns. The
external hold capacitor should not exceed 100pF.
2
®
®
SHM-12
GROUNDING AND LAYOUT
Obtaining fully specified performance from the SHM-12 requires
careful attention to pc-board layout and power supply decoupling.
For optimal performance, tie all grounds directly to a large ana-
log ground plane beneath and around the package. Bypass all
power supplies to ground with 10µF tantalum capacitors in paral-
lel with 0.1µF ceramic capacitors.
Locate the bypass capacitors as close to the unit as possible.
For best performance, controlled impedance transmission line
techniques, such as microstrip, should be used. Mount all com-
ponents as close to the required pins as possible. It is strongly
recommended that the SHM-12 not be socket-mounted.
50
Ω
SHM-12
1
–5V SUPPLY
0.1µF
2
–5V SUPPLY
4
INPUT
5
50
Ω
7
–5V SUPPLY
0.1µF
9
–5V SUPPLY
+5V SUPPLY
+5V SUPPLY
10µF
+
10
–5V SUPPLY
OUTPUT
R
Load
100
Ω
–5V SUPPLY
+5V SUPPLY
EXTERNAL HOLD
CAPACITOR
GROUND
13
12
11
0.1µF
0.1µF
+5V SUPPLY
17
15
14, 16
C
HO LD
SAMPLE / HOLD
SAMPLE / HOLD
19
50
Ω
SAMPLE
18
20
0.1µF
HOLD
ANALOG
INPUT
Refer to Table 1 for optional
HOLD capacitor value.
ANALOG
OUTPUT
10µF
Pin 3 is not connected;
do not connect pins 6 and 8.
0.1µF
0.1µF
+5V
–5V
Figure 2. SHM-12 Simplified Connection Diagram
-0.8 V
HOLD
-1.8 V
-0.8 V
SAMPLE
-1.8 V
+1 V
ANALOG
INPUT
-1 V
15ns typ.
+1 V
ANALOG
OUTPUT
-1 V
Feedthrough -80dB
Track-to-hold Settling
to ±0.024%
15ns typ.
7ns typ.
7ns typ.
Acquisition
Time to
±0.024%
SAMPLE
HOLD
SAMPLE
HOLD
Figure 3. SHM-12 Control and Timing
3
®
®
SHM-12
Evaluation Board
for CLCC-20 Version
0.1µF
130
Ω
–5V SUPPLY
16, 17, 18, 19
SAMPLE
SHM-12
1, 2
0.1µF
SAMPLE / HOLD
ANALOG
INPUT
20
–5V SUPPLY
19
SAMPLE / HOLD
82
Ω
130
Ω
14
18
17, 20
15
14, 16
13
12
11
0.1µF
0.1µF
C
HOLD
82
Ω
0.1µF
4
INPUT
+5V SUPPLY
EXTERNAL HOLD
CAPACITOR
HOLD
13
51
Ω
0.1µF
5, 7
–5V SUPPLY
GROUND
+5V SUPPLY
+5V SUPPLY
C
HOLD
= 100pF;
Refer to Table 1.
+5V SUPPLY
6, 7, 8, 9, 10
–5V SUPPLY
11, 12, 15
9, 10
0.1µF
–5V SUPPLY
OUTPUT
ANALOG
OUTPUT
5
GROUND
1, 2, 3, 4
GROUND PLANE
Figure 4. SHM-12 Evaluation Board Schematic
Table 1. Optional External HOLD Capacitor
Model
SHM-12L, -12S
SHM-12LM
Operating
Temperature Range
–40 to +85°C
–55 to +125°C
Type of HOLD Capacitor
(Ceramic,
≤100pF,
±10%)
Type I or II, NPO or X7R
Type I or NPO
4
®
®
SHM-12
INCHES
(mm)
0.43
(11)
0.13
(3.3)
PLASTIC
STANDOFF
(TOP VIEW)
0.85
(21.59)
0.100
(2.54)
20
19
18
17
C1
C5
R1
C2
C3
1
2
3
4
5
C4
C7
R4
R3
C
EXT
1
2
3
4
5
6
7
8
0.018
(0.45)
20
19
18
17
16
15
14
13
12
11
1.10
(27.94)
16
15
14
13
12
11
6
7
8
9
10
C6 R6
R5
9
10
(BOTTOM VIEW)
0.95
(24.13)
Figure 5. SHM-12 Evaluation Board Dimensions
SHM-12 Evaluation Board Connections
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
FUNCTION
GROUND
GROUND
GROUND
GROUND
ANALOG OUTPUT
+5V SUPPLY
+5V SUPPLY
+5V SUPPLY
+5V SUPPLY
+5V SUPPLY
–5V SUPPLY
–5V SUPPLY
HOLD
SAMPLE
–5V SUPPLY
–5V SUPPLY
–5V SUPPLY
–5V SUPPLY
–5V SUPPLY
ANALOG INPUT
5
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