NTE NTE3470

NTE3470
Integrated Circuit
Floppy Disk Read Amplifier System
Description:
The NTE3470 is a monolithic READ Amplifier System for obtaining digital information from floppy disk
storage. It is designed to accept the differential AC signal produced by the magnetic head and produce a digital output pulse that corresponds to each peak of the input signal. The gain stage amplifies
the input waveform and applies it to an external filter network, enabling the active differentiator and
time domain filter to produce the desired output.
Features:
D Combines All the Active Circuitry to Perform the Floppy Disk Read Amplifier Function in One Circuit
D Improved (Positive) Gain TC and Tolerance
D Improved Input Common Mode
Absolute Maximum Ratings: (TA = +25°C, Note 1 unless otherwise specified)
Power Supply Voltage (Pin11), VCC1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V
Power Supply Voltage (Pin18), VCC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V
Input Voltage (Pin1 and Pin2), VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.2 to +7.0V
Output Voltage (Pin10), VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.2 to +7.0V
Operating Ambient Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C
Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150°C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +150°C
Note 1. “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot
be guaranteed. They are not meant to imply that the device should be operated at these limits. The table of “Electrical Characteristics” provides conditions for actual device operation.
Recommended Operating Conditions:
Power Supply Voltage, VCC
(VCC1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +4.75 to +5.25V
(VCC2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +10 to +14V
Operating Ambient Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C
Electrical Characteristics: (TA = 0° to +70°C, VCC1 = 4.75 to 5.25V, VCC2 = 10 to 14V unless
otherwise specified)
Parameter
Differential Voltage Gain
Input Base Current
Input Common Mode Range,
Linear Operation
Symbol
AVD
Test Conditions
f = 200kHz, ViD = 7mVRMS
IIB
Min
Typ
Max
Unit
80
100
130
V/V
–
–10
–25
µA
viCM
5% Max THD
–0.1
–
1.5
V
Differential Input Voltage, Linear Operation
viD
5% Max THD
–
–
25
mVP–P
Output Voltage Swing Differential
voD
3
4
–
VP–P
Output Source Current, Toggled
IO
–
8.0
–
mA
Output Sink Current (Pin16 and Pin17)
IOS
2.8
4.0
–
mA
100
250
–
kΩ
Small Signal Input Resistance
ri
TA = +25°C
Small Signal Output Resistance,
Single Ended
ro
TA = +25°C, VCC1 = 5V,
VCC2 = 12V
–
15
–
Ω
viD = 2mVRMS, TA = +25°C,
VCC1 = 5V, VCC2 = 12V
10
–
–
MHz
TA = +25°C, f = 100kHz,
AVD = 40dB, vin = 200mVP–P,
VCC1 = 5V, VCC2 = 12V
50
–
–
dB
VCC1 Supply Rejection Ratio
TA = +25°C, VCC2 = 12V,
4.75V ≤ VCC1 ≤ 5.25V, AVD = 40dB
50
–
–
dB
VCC2 Supply Rejection Ratio
TA = +25°C, VCC1 = 5V,
10V ≤ VCC2 ≤ 14V, AVD = 40dB
50
–
–
dB
Bandwidth, –3dB
Common Mode Rejection Ratio
BW
CMRR
Differential Output Offset
VDO
TA = +25°C, viD = vin = 0V
–
–
0.4
V
Common Mode Output Offset
VCO
viD = vin = 0V, Differential and
Common Mode
–
3.0
–
V
Differential Noise Voltage Referred
to Input
en
TA = +25°C, BW = 10Hz to 1MHz
–
15
–
µVRMS
Supply Current
ICC
VCC1 = 5.25V, S1 to Pin12 or Pin13
–
40
–
mA
VCC2 = 14V
–
4.8
–
mA
1.0
1.4
–
mA
–
–
5
%
–
30
–
kΩ
–
40
–
Ω
Active Differentiator Section
Differentiator Output Sink Current,
Pin12 and Pin13
IOD
VOD = VCC1
Peak Shift
PS
Note 2
Differentiator Input Resistance,
Differential
riD
Differentiator Output Resistance,
Differential
roD
TA = +25°C
Note 2. f = 250kHz, viD = 1VP–P, icap = 500µA
tPS1 – tPS2
x 100%
tPS1 + tPS2
VCC1 = 5V, VCC2 = 12V
where PS = 1/2
Electrical Characteristics (Cont’d): (TA = 0° to +70°C, VCC1 = 4.75 to 5.25V, VCC2 = 10 to 14V
unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Digital Section
Output Voltage High Logic Level, Pin10
VOH
VCC1 = 4.75V, VCC2 = 12V,
IOH = –0.4mA
2.7
–
–
V
Output Voltage Low Logic Level, Pin10
VOL
VCC1 = 4.75V, VCC2 = 12V,
IOH = 8mA
–
–
0.5
V
Output Rise Time, Pin10
tTLH
–
–
20
ns
Output Fall Time, Pin10
tTHL
–
–
25
ns
t1A, t1B
500
–
4000
ns
85
–
115
%
150
–
1000
ns
85
–
115
%
Timing Range Mono #1 (t1A and t1B)
Timing Accuracy Mono #1
Et1
Timing Range Mono #2
t2
Timing Accuracy Mono #2
Et2
t1 = 1µs = 0.625 R1C1 + 200ns,
Note 3, Note 4, Note 5
t2 = 200ns = 0.625 R2C2,
Note 6, Note 7
Note 3. R1 = 6.4kΩ, C1 = 200pF.
Note 4. Accuracy guaranteed for R1 in the range 1.5kΩ ≤ R1 ≤ 10kΩ and C1 in the range 150pF ≤
C1 ≤ 680pF.
Note 5. To minimize current transients, C1 should be kept as small as is convenient.
Note 6. R2 = 1.6kΩ, C2 = 200pF.
Note 7. Accuracy guaranteed for R2 in the range 1.5kΩ ≤ R2 ≤ 10kΩ and C2 in the range 100pF ≤
C1 ≤ 800pF.
Pin Connection Diagram
Amplifier Input 1
18 VCC2
Amplifier Input 2
Offset Decoupling 3
17 Amplifier Output
16 Amplifier Output
Offset Decoupling 4
15 Active Differentiator Input
GND 5
14 Active Differentiator Input
One–Shot Component Mono #1 6
One–Shot Component Mono #1 7
One–Shot Component Mono #2 8
13 Differentiator Component
12 Differentiator Component
11 VCC1
One–Shot Component Mono #2 9
10 Data Output
18
10
.250
(6.35)
1
9
.870 (22.0) Max
.325 (8.25)
.160
(4.06)
Max
.100 (2.54) Typ
.800 (20.32)
.125 (3.17) Min