PHILIPS NE5521N Lvdt signal conditioner Datasheet

Philips Semiconductors Linear Products
Product specification
LVDT signal conditioner
NE/SA/SE5521
DESCRIPTION
PIN CONFIGURATIONS
The NE/SA/SE5521 is a signal conditioning circuit for use with
Linear Variable Differential Transformers (LVDTs) and Rotary
Variable Differential Transformers (RVDTs). The chip includes a low
distortion, amplitude-stable sine wave oscillator with programmable
frequency to drive the primary of the LVDT/RVDT, a synchronous
demodulator to convert the LVDT/RVDT output amplitude and phase
to position information, and an output amplifier to provide
amplification and filtering of the demodulated signal.
F, N Packages
AMP OUT 1
18 V+
+IN 2
17 C
T
–IN 3
16 V
REF
LVDT IN 4
15 FEEDBACK
DEMOD OUT 5
14 OSC
SYNC 6
13 OSC
GND 7
FEATURES
• Low distortion
• Single supply 5V to 20V, or dual supply ±2.5V to ±10V
• Oscillator frequency 1kHz to 20kHz
• Capable of ratiometric operation
• Low power consumption (182mV typ)
12 V
REF/2
N.C. 8
11 R
T
N.C. 9
10 N.C.
TOP VIEW
D1 Package
AMP OUT 1
16 V+
+IN 2
15 CT
–IN 3
14 V
REF
APPLICATIONS
• LVDT signal conditioning
• RVDT signal conditioning
• LPDT signal conditioning
• Bridge circuits
LVDT IN 4
13 FEEDBACK
DEMOD OUT 5
12 OSC
SYNC 6
11 OSC
GND 7
10 VREF/2
N.C. 8
9 RT
TOP VIEW
NOTE:
1. SOL — released in large SO package only.
ORDERING INFORMATION
TEMPERATURE RANGE
ORDER CODE
DWG #
18-Pin Plastic Dual In-Line Package (DIP)
DESCRIPTION
0 to +70°C
NE5521N
0407A
16-Pin Small Outline Large (SOL) Package
0 to +70°C
NE5521D
0171B
18-Pin Plastic Dual In-Line Package (DIP)
–40 to +85°C
SA5521N
0407A
18-Pin Ceramic Dual In-Line Package (CERDIP)
–55 to +125°C
SE5521F
0583A
16-Pin Ceramic Dual In-Line Package (CERDIP)
–40 to +85°C
SA5521D
0582B
ABSOLUTE MAXIMUM RATINGS
SYMBOL
RATING
UNIT
Supply voltage
+20
V
Split supply voltage
±10
V
TA
Operating temperature range
NE5521
SA5521
SE5521
0 to 70
–40 to +85
–55 to +125
°C
°C
°C
TSTG
Storage temperature range
–65 to +125
°C
PD
Power dissipation1
910
mW
VCC
PARAMETER
NOTES:
1. For derating, see typical power dissipation versus load curves (Figure 1).
August 31, 1994
901
853-0043 13721
Philips Semiconductors Linear Products
Product specification
LVDT signal conditioner
NE/SA/SE5521
BLOCK DIAGRAM
VREF
16
15
FEEDBACK
10k
10k
17
OSC
CT
RT
SINE
CONV
–
–
+
+
11
14
10k
V+
13
18
+IN
AMP
OUT
3
VREF/2
7
AUX AMP
–
2
OSC
12
10k
–IN
OSC
4
+
SYNCHRONOUS
DEMODULATOR
1
6
GND/V–
LVDT IN
SYNC
5
DOMOD OUT
NOTE:
Pin numbers are for F, N packages.
PIN DEFINITIONS FOR D, F AND N PACKAGES
PIN NO.
SYMBOL
DEFINITION
D
F, N
1
1
Amp Out
2
2
+IN
Auxiliary Amplifier non-inverting input.
3
3
–IN
Auxiliary Amplifier inverting input.
4
4
LVDT IN
5
5
DEMOD OUT
Pulsating DC output from the Synchronous Demodulator output. This voltage should be filtered before
use.
6
6
SYNC
Synchronizing input for the Synchronizing Demodulator. This input should be connected to the OSC or
OSC output. Sync is referenced to VREF/2.
7
7
GND
Device return. Should be connected to system ground or to the negative supply.
8
8
NC
No internal connection.
--
9
NC
No internal connection.
--
10
NC
No internal connection.
9
11
RT
A temperature stable 18kΩ resistor should be connected between this pin and Pin 7.
10
12
VREF/2
11
13
OSC
Oscillator sine wave output that is 180° out of phase with the OSC signal. The LVDT/RVDT primary is
usually connected between OSC and OSC pins.
12
14
OSC
Oscillator sine wave output. The LVDT/RVDT primaries are usually connected between OSC and OSC
pins.
13
15
FEEDBACK
14
16
VREF
Reference voltage input for the oscillator and sine converter. This voltage MUST be stable and must not
exceed +V supply voltage.
15
17
CT
Oscillator frequency-determining capacitor. The capacitor connected between this pin and ground should
be a temperature-stable type.
16
18
+V
Positive supply connection.
August 31, 1994
Auxiliary Amplifier Out.
Input to Synchronous Demodulator from the LVDT/RVDT secondary.
A high impedance source of one half the potential applied to VREF. The LVDT/RVDT secondary return
should be to this point. A bypass capacitor with low impedance at the oscillator frequency should also be
connected between this pin and ground.
Usually connected to the OSC output for unity gain, a resistor between this pin and OSC, and one between this pin and ground can provide for a change in the oscillator output pin amplitudes.
902
Philips Semiconductors Linear Products
Product specification
LVDT signal conditioner
NE/SA/SE5521
DC ELECTRICAL CHARACTERISTICS
V+ = VREF = 10V, TA = 0 to 70°C for NE5521, TA = –55 to +125°C for SE5521, TA = –40 to 85°C for SA5521, Frequency = 1kHz, unless
otherwise noted.
SYMBOL
PARAMETER
TEST CONDITIONS
NE5521
Min
SA/SE5521
Typ
Max
Min
Typ
Max
UNIT
VCC
Supply current
12.9
20
12.9
18
mA
IREF
Reference current
5.3
8
5.3
8
mA
VREF
Reference voltage range
V+
V
182
280
182
260
mW
PD
5
Power dissipation
V+
5
Oscillator Section
Oscillator output
THD
RL = 10kΩ
V REF
8.8
V REF
8.8
1.5
VRMS
Sine wave distortion
No load
1.5
Initial amplitude error
TA = 25°C
0.4
±3
0.4
±3
%
0.005
0.01
0.005
0.01
%/°C
±0.9
±5
±0.9
±5
Tempco of amplitude
Init. accuracy of oscillator freq.
TA = 25°C
Temperature coeff. of frequency1
0.05
Voltage coeff. of frequency
2.5
Min OSC (OSC) Load2
300
170
300
%
%
0.05
%/°C
3.3
%/V(VREF)
170
Ω
Demodulator Section
∈r
Linearity error
±0.05
5VP-P input
Maximum demodulator input
VOS
TCVOS
IBIAS
Demodulator offset voltage
Demodulator offset voltage drift
Demodulator input current
–600
VR/2 accuracy
±0.1
±0.05
V REF
2
±1.4
±5
V REF
2
±1.4
±5
mV
5
25
5
25
µV/5C
–234
–500
±0.1
±1
±0.5
±5
±0.1
%FS
VP-P
–234
nA
±0.1
±1
%
±0.5
±5
mV
Auxiliary Output Amplifier
VOS
Input offset voltage
IBIAS
Input bias current
IOS
Input offset current
AV
Gain
SR
Slew rate
GBW
Unity gain bandwidth product
–600
–210
10
100
–500
50
385
10
100
1.3
AV = 1
1.6
Output voltage swing
RL = 10kΩ
Output short circuit current to
ground or to VCC
TA = 25°C
7
8.2
42
7
100
–210
nA
50
nA
385
V/mV
1.3
V/µs
1.6
MHz
8.2
V
42
100
mA
NOTES:
1. This is temperature coefficient of frequency for the device only. It is assumed that CT and RT are fixed in value and CT leakage is fixed over
the operating temperature range.
2. Minimum load impedance for which distortion is guaranteed to be less than 5%.
August 31, 1994
903
Philips Semiconductors Linear Products
Product specification
LVDT signal conditioner
NE/SA/SE5521
DEFINITION OF TERMS
Oscillator Output
RMS value of the AC voltage at the oscillator output pin. This output is referenced to VREF/2
and is a function of VREF.
Sine Wave Distortion
The Total Harmonic Distortion (THD) of the oscillator output with no load. This is not a
critical specification in LVDT/RVDT systems. This figure could be 15% or more without
affecting system performance.
Initial Amplitude Error
A measure of the interchangeability of NE/SA/SE5521 parts, not a characteristic of any one
part. It is the degree to which the oscillator output of a number of NE/SA/SE5521 samples
will vary from the median of that sample.
Initial Accuracy of Oscillator Frequency
Another measure of the interchangeability of individual NE/SA/SE5521 parts. This is the
degree to which the oscillator frequency of a number of NE/SA/SE5521 samples will vary
from the median of that sample with a given timing capacitor.
Tempco of Oscillator Amplitude
A measure of how the oscillator amplitude varies with ambient temperature as that
temperature deviates from a 25°C ambient.
Tempco of Oscillator Frequency
A measure of how the oscillator frequency varies with ambient temperature as that
temperature deviates from a 25°C ambient.
Voltage Coefficient of Oscillator Frequency
The degree to which the oscillator frequency will vary as the reference voltage (VREF)
deviates from +10V.
Min OSC (OSC) Load
Minimum load impedance for which distortion is guaranteed to be less than 5%.
Linearity Error
The degree to which the DC output of the demodulator/amplifier combination matches a
change in the AC signal at the demodulator input. It is measured as the worst case
nonlinearity from a straight line drawn between positive and negative fullscale end points.
Maximum Demodulator Input
The maximum signal that can be applied to the demodulator input without exceeding the
specified linearity error.
APPLICATION INFORMATION
OSC frequency V REF 1.3V
V REF (R T 1.5k) C T
DEVICE POWER DISSIPATION (mW)
2000
PDMAX (N PACKAGE)
1000
AT TA = 70°C, TJ(MAX) = +150°C
800
PDMAX (SO PACKAGE)
AT TA = +85°C, TJ(MAX) = +150°C
700
600
VREF = V+ = 20V
500
PDMAX (F PACKAGE)
AT TA = +125°C, TJ(MAX) = +165°C
400
PDMAX (F PACKAGE)
AT TA = +125°C, TJ(MAX) = +150°C
15V
300
10V
200
5V
100
0.2
0.4
0.6
0.8
1 2
3
OSC–OSC LOAD (kΩ)
Figure 1. Device Power Dissipation vs OSC – OSC Load at +25°C
August 31, 1994
904
Philips Semiconductors Linear Products
Product specification
LVDT signal conditioner
NE/SA/SE5521
16
16
14
8
ICC
12
I(mA)
∆fOSC
(%) 0
10
8
–8
6
–16
5
8
10
12
14
16
18
4
–55
20
VCC = VREF (V)
I(mA)
ICC
IREF
5
0
5
10
15
20
25
VCC = VREF (V)
Figure 3. IREF and ICC vs Voltage (TA = +25°C)
August 31, 1994
0
25
70 85 125
Figure 4. IREF and ICC vs Temperature
(VREF = VCC = 10V)
20
10
–40
TA (°C)
Figure 2. Oscillator Frequency Variation With Voltage
(Normalized to VREF = VCC = 10V) TA = +25°C
15
IREF
905
Similar pages