The AD537 is a monolithic V-F converter consisting of an input amplifier, a precision oscillator system, an accurate internal reference generator and a high current output stage. Only a single external RC network is required to set up any full-scale (F.S.) frequency up to 100 kHz and any F.S. input voltage up to ±30 V. Linearity error is as low as ±0.05% for 10 kHz F.S., and operation is guaranteed over an 80 dB dynamic range. The overall temperature coefficient (excluding the effects of external components) is typically ±30 ppm/°C. The AD537 operates from a single supply of 5 V to 36 V and consumes only 1.2 mA quiescent current.
A temperature-proportional output, scaled to 1.00 mV/K, enables the circuit to be used as a reliable temperature-to-frequency converter; in combination with the fixed reference output of 1.00 V, offset scales such as 0°C or 0°F can be generated.
The low drift (1µV/°C typ) input amplifier allows operation directly from small signals (e.g., thermocouples or strain gages) while offering a high (250 M(Ohm) input resistance. Unlike most V-F converters, the AD537 provides a square-wave output, and can drive up to 12 TTL loads, LEDs, very long cables, etc.
The excellent temperature characteristics and long-term stability of the AD537 are guaranteed by the primary bandgap reference generator and the low T.C. silicon chromium thin film resistors used throughout.
The device is available in either a TO-116 ceramic DIP or a TO-100 metal can; both are hermetically sealed packages.
The AD537 is available in three performance/temperature grades; the J and K grades are specified for operation over the 0°C to +70°C range while the AD537S is specified for operation over the extended temperature range, -55°C to +125°C.
Features and Benefits
| Analog to Digital Converters |
| Document | note |
| AD537: Integrated Circuit Voltage-to-Frequency Converter Data Sheet (Rev. C) | PDF 179 kB |
| Document | note |
| Part Number | Package | Packing Qty | Temp Range | Price 100-499 | Price 1000+ | RoHS |
|---|---|---|---|---|---|---|
| AD537JCHIPS Production | CHIPS OR DIE | REEL 140 | 25C | 16.46 | 16.46 | Y |
| AD537JD Production | 14 ld Side-Brazed CerDIP | OTH 25 | 0 to 70C | 50.25 | 45.43 | N |
| AD537JH Production | ROUND HEADER/METAL CAN | OTH 100 | 0 to 70C | 13.06 | 11.8 | N |
| AD537KD Production | 14 ld Side-Brazed CerDIP | OTH 25 | 0 to 70C | 78.9 | 71.31 | N |
| AD537KH Production | ROUND HEADER/METAL CAN | OTH 100 | 0 to 70C | 22.12 | 19.99 | N |
| AD537SD Production | 14 ld Side-Brazed CerDIP | OTH 25 | -55 to 125C | 115.11 | 104.07 | N |
| AD537SD/883B Production | 14 ld Side-Brazed CerDIP | OTH 25 | -55 to 125C | 199.48 | 180.32 | N |
| AD537SH Production | ROUND HEADER/METAL CAN | OTH 100 | -55 to 125C | 43.47 | 39.29 | N |
| AD537SH/883B Production | ROUND HEADER/METAL CAN | OTH 100 | -55 to 125C | 90.99 | 82.25 | N |
