NTE NTE995M Datasheet

NTE995 & NTE995M

Integrated Circuit

Frequency–to–Voltage Converter

Description:

The NTE995 (14–Lead DIP) and NTE995M (8–Lead DIP) are monolithic frequency to voltage con­verters with a high gain OP amp/comparator designed to operate a relay, lamp, or other load when
the input frequency reaches or exceeds a selected rate. The tachometer uses a charge pump tech­nique and offers frequency doubling for low ripple, full input protection, and its output swings to GND
for a zero frequency input.

Advantages:

D Output Swing to GND for Zero Frequency Input
D Easy to Use: V
D Only One RC Network Provides Frequency Doubling
D Zener Regulator On Chip Allows Accurate and Stable Frequency to Voltage or Current Conversion

Features:

D Ground Referenced Tachometer Input Interfaces Directly with Variable Reluctance Magnetic

Pickups

D OP Amp/Comparator has Floating Transistor Output
D 50mA Sink or Source to Operate Relays, Solenoids, Meters, or LEDs
D Frequency Doubling for Low Ripple
D Tachometer has Built–In Hysteresis with Either Differential Input or Ground Referenced Input
D Built–In Zener Diode
D ±0.3% Linearity Typical
D Ground Referenced Tachometer is Fully Protected from damage Due to Swings Above V

and Below GND

= fIN x VCC x R1 x C1

OUT

CC

Applications:

D Over/Under Speed Sensing
D Frequency to Voltage Conversion (Tachometer)
D Speedometers
D Breaker Point Dwell Meters
D Hand–Held Tachometer
D Speed Governors

D Cruise Control
D Automotive Door Lock Control
D Clutch Control
D Horn Control
D Touch or Sound Switches

Absolute Maximum Ratings:

Supply Voltage, V

CC

Supply Current (Zener Options) 25mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Collector Voltage 28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Differential Input Voltage

Tachometer 28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OP Amp/Comparator 28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input Voltage Range

Tachometer

NTE995M ±28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NTE955 0.0V to +28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OP Amp/Comparator 0.0V to +28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Dissipation (Note 1), P

D

NTE995M 1200mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NTE995 1580mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Temperature Range, T
Storage Temperature Range, T
Lead Temperature, T

L

stg

opr

–40° to +85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–65° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NTE995, NTE995M (During Soldering, 10sec) +260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NTE995M

(Vapor Phase, 60sec) +215°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(Infrared, 15sec) +220°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Note 1. For operation in ambient temperatures above 25°C, the device must be derated based on

a +150°C maximum junction temperature and a thermal resistance of +101°C/W junction to
ambient for the NTE995M, and +79°C/W junction to ambient for the NTE995.

Electrical Characteristics:

Parameter Symbol Test Conditions Min Typ Max Unit

Tachometer

Input Thresholds VIN = 250mV
Hysteresis VIN = 250mV
Offset Voltage

NTE995

NTE995M – 5.0 15 mV
Input Bias Current VIN = ±50mV – 0.1 1.0 µA
Output Voltage (High Level, Pin2) V
Output Voltage (Low Level, Pin2) V
Output Current I2, I
Leakage Current I
Gain Constant K Note 3 0.9 1.0 1.1
Linearity fIN = 1kHz, 5kHz, 10kHz, Note 5 –1.0 0.3 +1.0 %

(VCC = 12V, TA = +25°C unless otherwise specified)

@ 1kHz, Note 2 ±10 ±25 ±40 mV

P–P

@ 1kHz, Note 2 – 30 – mV

P–P

OH

OL

3

VIN = 250mV

VIN = +125mV, Note 3 – 8.3 – V
VIN = –125mV, Note 3 – 2.3 – V
V2 = V3 = 6V, Note 4 140 180 240 µA

3

I2 = 0, V3 = 0 – – 0.1 µA

@ 1kHz, Note 2

P–P

– 3.5 10 mV

Note 2. Hysteresis is the sum + VTH – (–VTH), offset voltage is their difference.
Note 3. V

is equal to 3/4 x VCC – 1 VBE, VOL is equal to 1/4 x VCC – 1 VBE therefore VOH – VOL = VCC/2.

OH

The difference, V

– VOL, and the mirror gain, I2/I3, are two factors that cause the tachometer

OH

gain constant to vary from 1.0.

Note 4. Be sure when choosing the time constant R1 x C1 that R1 is such that the maximum antici-

pated output voltage at Pin3 can be reached with I

x R1. The maximum value for R1 is lim-

3

ited by the output resistance of Pin3 which is greater than 10MΩ typically.

Note 5. Nonlinearity is defined as the deviation of V

defined by the V

@ 1kHz and V

OUT

@ 10kHz. C1 = 1000pF, R1 = 68k and C2 = 0.22mFd.

OUT

(@ Pin3) for fIN = 5kHz from a straight line

OUT