Datasheet CS8191XDWF20, CS8191XNF16, CS8191XDWFR20 Datasheet (Cherry Semiconductor)

1

Features

■ Direct Sensor Input

■ High Output Torque

■ Wide Output Voltage

Range

■ High Impedance Inputs

■ Accurate down to 10V V

CC

■ Fault Protection

Overvoltage
Short Circuit

■ Low Voltage Operation

Package Options

16 Lead PDIP

(internally fused leads)

CS8191

Precision Air-Core Tach/Speedo Driver

with Short Circuit Protection

20 Lead SOIC

(internally fused leads)

1

CP+

2

3

4

5

6

7

8

SQ

OUT

FREQ

IN

NC

Gnd

Gnd

NC

COS+

16

15

14

13

12

11

10

CP-

F/V

OUT

V

REG

NC

Gnd

Gnd

NC

SIN+

9

COS-

SIN-

17

18

V

CC

BIAS

19

20

Description

Block Diagram

Absolute Maximum Ratings

The CS8191 is specifically designed
for use with 4 quadrant air-core
meter movements. The IC includes
an input comparator for sensing
input frequency such as vehicle
speed or engine RPM, a charge
pump for frequency to voltage con­version, a bandgap reference for
stable operation and a function
generator with sine and cosine

amplifiers that differentially drive
the motor coils.

The CS8191 has a higher torque
output and better output signal
symmetry than other competitive
parts (CS289, and LM1819). It is
protected against short circuit and
overvoltage (60V) fault conditions.
Enhanced circuitry permits func­tional operation down to 8V.

CS8191

Supply Voltage ( ² 100ms pulse transient) ...........................................V

CC

= 60V

(continuous)..................................................................V

CC

= 24V

Operating Temperature Range ........................................................-40¡C to +105¡C

Junction Temperature Range ...........................................................-40¡C to +150¡C

Storage Temperature Range.............................................................-55¡C to +165¡C

Electrostatic Discharge (Human Body Model)...................................................4kV

Lead Temperature Soldering

Wave Solder (through hole styles only)..................10 sec. max, 260¡C peak

Reflow (SMD styles only)...................60 sec. max above 183¡C, 230¡C peak

Rev 3/9/99

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

¨

BIAS

SQ

FREQ

CP+

OUT

IN

Charge Pump

Input

Comp.

+

Ð

+

Ð

Voltage

Regulator

F/V

CP-

V

OUT

REG

V

1

CC

V

2

REG

BIAS

3

4

Gnd

5

Gnd

COS-

6

SINE-

7

FREQ

8

IN

16

15

14

13

12

11

10

9

F/V

CP+

CP-

Gnd

Gnd

COS+

SINE+

SQ

OUT

OUT

Gnd

Gnd

COS

COS

V

V

REG

7.0V

+

COS

Output

-

CC

Ð

+

+

Ð

High Voltage, Short

Circuit Protection

Function

Generator

Ð

+

SINE

Output

+

Ð

Gnd

Gnd

SINE+

SINE-

2

Electrical Characteristics: -40¡C ² TA² 105¡C, 8V ² VCC² 16V unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS8191

■ Supply Voltage Section

ICCSupply Current VCC= 16V, -40¡C, No Load 70 125 mA

VCCNormal Operation Range

8.0 13.1 16.0 V

■ Input Comparator Section

Positive Input Threshold 2.4 2.7 3.0 V

Negative Input Threshold 2.0 2.3 V

Input Hysteresis 200 400 1000 mV

Input Bias Current * 0V ² VIN² 8V -2 ±10 µA

Input Frequency Range 0 20 kHz

Input Voltage Range in series with 1k½ -1 V

CC

V

Output V

SAT

ICC= 10mA 0.15 0.40 V

Output Leakage V

CC

= 7V 10 µA

Logic 0 Input Voltage 2.0 V

*Note: Input is clamped by an internal 12V Zener.

■ Voltage Regulator Section

Output Voltage 6.50 7.00 7.50 V

Output Load Current 10 mA

Output Load Regulation 0 to 10 mA 10 50 mV

Output Line Regulation 8.0V ² VCC² 16V 20 150 mV

Power Supply Rejection VCC= 13.1V, 1VP/P1kHz 34 46 dB

■ Charge Pump Section

Inverting Input Voltage 1.5 2.0 2.5 V

Input Bias Current 40 150 nA

V

BIAS

Input Voltage 1.5 2.0 2.5 V

Non Invert. Input Voltage IIN= 1mA 0.7 1.1 V

Linearity* @ 0, 87.5, 175, 262.5, + 350Hz -0.10 0.28 +0.70 %

F/V

OUT

Gain @ 350Hz, CT= 0.0033µF, RT= 243k½ 7 10 13 mV/Hz

Norton Gain, Positive IIN= 15µA 0.9 1.0 1.1 I/I

Norton Gain, Negative IIN= -15µA 0.9 1.0 1.1 I/I

*Note: Applies to % of full scale (270¡).

■ Function Generator Section: -40¡ ² T

A

² 85¡C, VCC= 13.1V unless otherwise noted.

Differential Drive Voltage 10V ² VCC² 16V 7.5 8.0 8.5 V

(V

COS

+ - V

COS

-) Q = 0¡

Differential Drive Voltage 10V ² VCC² 16V 7.5 8.0 8.5 V

(V

SIN

+ - V

SIN

-) Q = 90¡

Differential Drive Voltage 10V ² VCC² 16V -8.5 -8.0 -7.5 V

(V

COS

+ - V

COS

-) Q = 180¡

Differential Drive Voltage 10V ² VCC² 16V -8.5 -8.0 -7.5 V

(V

SIN

+ - V

SIN

-) Q = 270¡

Differential Drive Load 10V ² VCC² 16V, -40¡C 178 ½

25¡C 239 ½

105¡C 314 ½

Zero Hertz Output Voltage -0.08 0.0 +0.08 V

3

PACKAGE LEAD # LEAD SYMBOL FUNCTION

CS8191

Electrical Characteristics:

continued

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Package Lead Description

Typical Performance Characteristics

0 45 90 135 180 225 270 315

Output Voltage (V)

Degrees of Deflection (°)

7

6

5

4

3
2

1

0

-1

-2

-3

-4

-5

-6

-7

COS

SIN

045

90

135 180 225 270 315

F/V Output (V)

Frequency/Output Angle (°)

7

6

5

4

3

2

1

0

Figure 2: Charge Pump Output Voltage vs Output Angle

Figure 1: Function Generator Output Voltage

vs Degrees of Deflection

F/V

OUT

= 2.0V + 2 FREQ ´ CT´ RT´ (V

REG

- 0.7)

■ Function Generator Section: continued

Function Generator Error * Q = 0¡ to 225¡ -2 0 +2 deg

Reference Figures 1 - 4 Q = 226¡ to 305¡ -3 0 +3 deg

Function Generator Error 13.1V ² V

CC

² 16V -1 0 +1 deg

Function Generator Error 13.1V ² V

CC

² 10V -1 0 +1 deg

Function Generator Error 13.1V ² V

CC

² 8.0V -7 0 +7 deg

Function Generator Error 25¡C ² T

A

² 80¡C -2 0 +2 deg

Function Generator Error 25¡C ² T

A

² 105¡C -4 0 +4 deg

Function Generator Error Ð40¡C ² T

A

² 25¡C -2 0 +2 deg

Function Generator Gain T

A

= 25¡C, Q vs F/V

OUT

60 77 95 ¡/V

*Note: Deviation from nominal per Table 1 after calibration at 0¡ and 270¡.

16L PDIP 20L SO

11VCCIgnition or battery supply voltage.

22V

REG

Voltage regulator output.

3 3 BIAS Test point or zero adjustment.

4, 5, 12, 13 5, 6, 15, 16 Gnd Ground Connections.

6 8 COS- Negative cosine output signal.

7 9 SIN- Negative sine output signal.

8 10 FREQ

IN

Speed or rpm input signal.

911SQ

OUT

Buffered square wave output signal.

10 12 SIN+ Positive sine output signal.

11 13 COS+ Positive cosine output signal.

14 18 CP- Negative input to charge pump.

15 19 CP+ Positive input to charge pump.

16 20 F/V

OUT

Output voltage proportional to input signal frequency.

4, 7, 14, 17 NC No connection.

4

CS8191

Nominal Angle vs. Ideal Angle (After calibrating at 180¡)

+7V

Ð7V

(V

COS+

) - (V

COS-

)

7V

Angle

-7V

Q

(V

SINE+

) - (V

SINE-

)

]

V

SIN+

Ð V

SIN-

V

COS+

Ð V

COS-

Q = ARCTAN

[

-1.50

Deviation (°)

0 45 90 135 180 225 270 315

-1.25

-1.00

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

1.00

1.25

1.50

Theoretical Angle (°)

Figure 4: Nominal Output Deviation

Figure 3: Output Angle in Polar Form

Ideal Angle (Degrees)

Nominal Angle (Degrees)

0

5

10

15

20

25

30

35

40

45

1 5 9 13 17 21 25 29 33 37 41 45

Ideal Degrees

Nominal Degrees

Typical Performance Characteristics: continued

00
1 1.09
2 2.19
3 3.29
4 4.38
5 5.47
6 6.56
7 7.64
8 8.72

9 9.78
10 10.84
11 11.90
12 12.94
13 13.97
14 14.99
15 16.00
16 17.00

17 17.98
18 18.96
19 19.92
20 20.86
21 21.79
22 22.71
23 23.61
24 24.50
25 25.37
26 26.23
27 27.07
28 27.79
29 28.73
30 29.56
31 30.39
32 31.24
33 32.12

34 33.04
35 34.00
36 35.00
37 36.04
38 37.11
39 38.21
40 39.32
41 40.45
42 41.59
43 42.73
44 43.88
45 45.00
50 50.68
55 56.00
60 60.44
65 64.63
70 69.14

75 74.00
80 79.16
85 84.53
90 90.00

95 95.47
100 100.84
105 106.00
110 110.86
115 115.37
120 119.56
125 124.00
130 129.32
135 135.00
140 140.68
145 146.00
150 150.44
155 154.63

160 159.14
165 164.00
170 169.16
175 174.33
180 180.00
185 185.47
190 190.84
195 196.00
200 200.86
205 205.37
210 209.56
215 214.00
220 219.32
225 225.00
230 230.58
235 236.00
240 240.44

245 244.63
250 249.14
255 254.00
260 259.16
265 264.53
270 270.00
275 275.47
280 280.84
285 286.00
290 290.86
295 295.37
300 299.21
305 303.02

Ideal Q Nominal Ideal Q Nominal Ideal Q Nominal Ideal Q Nominal Ideal Q Nominal Ideal Q Nominal

Degrees Q Degrees Degrees Q Degrees Degrees Q Degrees Degrees Q Degrees Degrees Q Degrees Degrees Q Degrees

Table 1: Function Generator Output Nominal Angle vs. Ideal Angle (After calibrating at 270¡)

Note: Temperature, voltage and nonlinearity not included.

Note: Temperature, voltage and nonlinearity not included.

5

The CS8191 is specifically designed for use with air-core
meter movements. It includes an input comparator for
sensing an input signal from an ignition pulse or speed
sensor, a charge pump for frequency to voltage conver­sion, a bandgap voltage regulator for stable operation,
and a function generator with sine and cosine amplifiers
to differentially drive the motor coils.

From the simplified block diagram of Figure 5A, the
input signal is applied to the FREQINlead, this is the
input to a high impedance comparator with a typical pos­itive input threshold of 2.7V and typical hysteresis of

0.4V. The output of the comparator, SQ

OUT

, is applied to
the charge pump input CP+ through an external capacitor
CT. When the input signal changes state, CTis charged
or discharged through R3 and R4. The charge accumulat­ed on CTis mirrored to C4 by the Norton Amplifier cir­cuit comprising of Q1, Q2 and Q3. The charge pump out­put voltage, F/V

OUT

, ranges from 2V to 6.3V depending
on the input signal frequency and the gain of the charge
pump according to the formula:

F/V

OUT

= 2.0V + 2 ´ FREQ ´ CT´ RT´ (V

REG

Ð 0.7V)

RTis a potentiometer used to adjust the gain of the F/V
output stage and give the correct meter deflection. The
F/V output voltage is applied to the function generator
which generates the sine and cosine output voltages. The
output voltage of the sine and cosine amplifiers are
derived from the on-chip amplifier and function genera­tor circuitry. The various trip points for the circuit (i.e., 0¡,
90¡, 180¡, 270¡) are determined by an internal resistor
divider and the bandgap voltage reference. The coils are
differentially driven, allowing bidirectional current flow
in the outputs, thus providing up to 305¡ range of meter
deflection. Driving the coils differentially offers faster
response time, higher current capability, higher output
voltage swings, and reduced external component count.
The key advantage is a higher torque output for the
pointer.

The output angle, Q, is equal to the F/V gain multiplied
by the function generator gain:

Q = A

F/V

´ AFG,

where:

A

FG

= 77¡/V (typ)

The relationship between input frequency and output
angle is:

Q = AFG´ 2 ´ FREQ ´ CT´ RT´ (V

REG

Ð 0.7V)

or, Q = 970 ´ FREQ ´ C

T

´ R

T

The ripple voltage at the F/V converterÕs output is deter­mined by the ratio of CTand C4 in the formula:

ÆV =

Ripple voltage on the F/V output causes pointer or nee­dle flutter especially at low input frequencies.

The response time of the F/V is determined by the time
constant formed by RTand C4. Increasing the value of C4
will reduce the ripple on the F/V output but will also
increase the response time. An increase in response time
causes a very slow meter movement and may be unac­ceptable for many applications.

Design Example

Maximum meter Deflection = 270¡
Maximum Input Frequency = 350Hz

1. Select RTand C

T

Q = A

GEN

´ Æ

F/V

Æ

F/V

= 2 ´ FREQ ´ CT´ RT´ (V

REG

Ð 0.7V)

Q = 970 ´ FREQ ´ CT´ R

T

Let CT= 0.0033µF, Find R

T

RT=

RT= 243k½

RTshould be a 250k½ potentiometer to trim out any inac­curacies due to IC tolerances or meter movement pointer
placement.

2. Select R3 and R4

Resistor R3 sets the output current from the voltage regu­lator. The maximum output current from the voltage reg­ulator is 10mA, R3 must ensure that the current does not
exceed this limit.

Choose R3 = 3.3k½

The charge current for C

T

is:

= 1.90mA

C1 must charge and discharge fully during each cycle of
the input signal. Time for one cycle at maximum frequen­cy is 2.85ms. To ensure that CTis discharged, assume that
the (R3 + R4) CTtime constant is less than 10% of the
minimum input frequency pulse width.

T = 285µs

Choose R4 = 1k½.

Charge time: T = R3 ´ C

T

= 3.3k½ ´ 0.0033µF = 10.9µs

Discharge time:T = (R3 + R4)C

T

= 4.3k½ ´ 0.0033µF = 14.2µs

3. Determine C4

C4 is selected to satisfy both the maximum allowable rip­ple voltage and response time of the meter movement.

C4 =

With C4 = 0.47µF, the F/V ripple voltage is 44mV.
Figure 7 shows how the CS8191 and the CS8441 are used

to produce a Speedometer and Odometer circuit.

CT(V

REG

Ð 0.7V)

V

RIPPLE(MAX)

V

REG

Ð 0.7V

3.3k½

270¡

970 ´ 350Hz ´ 0.0033µF

C

T(VREG

Ð 0.7V)

C4

Circuit Description and Application Notes

CS8191

+

Ð

R

T

C4

CPÐ

+

Ð

F/V

OUT

F to V

2.5V

Q2

Q1

Q3

0.25V

CP+

R4C

T

VC(t)

+Ð

R3

V

REG

SQ

OUT

Q

SQUARE

2.7V

FREQ

IN

T

PW T-PW

FREQ

IN

I

CP+

SQ

OUT

V

CC

V

REG

0

0

0

V

CP+

Figure 5A: Partial Schematic of Input and Charge Pump

Figure 5B: Timing Diagram of FREQINand I

C

P

6

CS8191

Circuit Description and Application Notes: continued

7

CS8191

Speedometer/Odometer or Tachometer Application

In some cases a designer may wish to use the CS8191 only
as a driver for an air-core meter having performed the F/V
conversion elsewhere in the circuit.

Figure 8 shows how to drive the CS8191 with a DC voltage
ranging from 2V to 6V. This is accomplished by forcing a
voltage on the F/V

OUT

lead. The alternative scheme shown
in figure 9 uses an external op amp as a buffer and operates
over an input voltage range of 0V to 4V.

Figure 8. Driving the CS8191 from an external DC voltage.

An alternative solution is to use the CS4101 which has a
separate function generator input lead and can be driven
directly from a DC source. Figure 8 and 9 are not tempera­ture compensated.

Figure 9. Driving the CS8191 from an external DC voltage using an Op

Amp Buffer.

Figure 6

R1 - 3.9, 500mW

R2 - 10k½
R3 - 3k½
R4 - 1k½
R

T

- Trim Resistor +/- 20 PPM/DEG. C

C1 - 0.1µF
C2 - With CS-8441 application, 10µF
C3 - 0.1µF
C4 - 0.47µF
C

T

- 0.0033µF, +/- 30 PPM/¡C

D1 - 1A, 600 PIV
D2 - 50V, 500mW Zener

Note 1: The product of C

T

and RThave a direct effect on gain and

therefore directly effect temperature compensation.

Note 2: C4 Range; 20pF to .2µF.
Note 3: R4 Range; 100k½ to 500k½.

Figure 7

Note 4: The IC must be protected from transients above 60V and reverse

battery conditions.

Note 5: Additional filtering on the FREQ

IN

lead may be required.

Ground

Battery

D1

R2

Typical Speedometer

Input

CP+

V

CC

V

REG

BIAS

Gnd

Gnd

COS-

SINE-

FREQ

CS8191

IN

SINE

COSINE

COS+

SINE+

SQ

F/V

CP+

CP-

Gnd

Gnd

OUT

16

OUT

15

14

13

12

11

10

9

C4

Air Core

Gauge

Speedometer

R

+

T

R4

R3

C

T

Battery

R1

D1

Ground

R2

Typical Speedometer

Input

1

CC

2

V

C1

D2

C3

C2

REG

BIAS

3

Gnd

4

Gnd

5

COS-

6

SINE-

7

8

FREQ

1

IN

SINE

COSINE

OUT

CP+

CP-

Gnd

Gnd

CS8191

COS+

SINE+

SQ

OUT

16

15

14

13

12

11

10

9

Speedometer

Air Core

Gauge

C4

R

+

T

R4

R3

C

T

F/V

V

CP+

CS8441

R1

C1

D2

C3

1

2

3

4

5

6

7

8

VREG

V

IN

2V to 6V DC

100kW

10kW

N/C

F/VOUT

CP

-

BIAS

CS8191

-

+

Air Core

Stepper Motor

200W

Odometer

BIAS

CP

CS8191

+

-

-

V

IN

0V to 4V DC

100kW

100kW

+

-

100kW

100kW

10kW

F/VOUT

D

Lead Count Metric English

Max Min Max Min
16L PDIP (internally fused leads) 19.69 18.67 .775 .735
20L SOIC (internally fused leads) 13.00 12.60 .512 .496

8

Rev. 3/9/99

CS8191

Thermal Data 16L PDIP* 20L SOIC*

R

QJC

typ

15 9 ûC/W

R

QJA

typ 50 55 ûC/W

Package Specification

PACKAGE DIMENSIONS IN mm (INCHES)

PACKAGE THERMAL DATA

Part Number Description

CS8191XNF16 16L PDIP (internally fused leads)
CS8191XDWF20 20L SOIC (internally fused leads)
CS8191XDWFR20 20L SOIC (internally fused leads)

(tape & reel)

Ordering Information

© 1999 Cherry Semiconductor Corporation

Cherry Semiconductor Corporation reserves the
right to make changes to the specifications without
notice. Please contact Cherry Semiconductor
Corporation for the latest available information.

Plastic DIP (N); 300 mil wide

0.39 (.015)
MIN.

2.54 (.100) BSC

1.77 (.070)

1.14 (.045)

D

Some 8 and 16 lead
packages may have
1/2 lead at the end
of the package.
All specs are the same.

.203 (.008)

.356 (.014)

REF: JEDEC MS-001

3.68 (.145)

2.92 (.115)

8.26 (.325)

7.62 (.300)

7.11 (.280)

6.10 (.240)

.356 (.014)

.558 (.022)

1.27 (.050) BSC

7.60 (.299)

7.40 (.291)

10.65 (.419)

10.00 (.394)

D

0.32 (.013)

0.23 (.009)

1.27 (.050)

0.40 (.016)

REF: JEDEC MS-013

2.49 (.098)

2.24 (.088)

0.51 (.020)

0.33 (.013)

2.65 (.104)

2.35 (.093)

0.30 (.012)

0.10 (.004)

Surface Mount Wide Body (DW); 300 mil wide

*Internally Fused Leads