ZN448E ETC-unknow, ZN448E Datasheet
ZN448E
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ZN448E Summary of contents
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... Choice of Linearity: 0.5 LSB - ZN448, 1 LSB - ZN449 On-Chip Clock Choice of On-Chip or External Reference Voltage Unipolar or Bipolar Input Ranges Commercial Temperature Range ORDERING INFORMATION Linearity Operating Device type error (LSB) temperature ZN448E 0 +70 C ZN449D +70 C ZN449E + ANALOGUE ...
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ZN448/9 ABSOLUTE MAXIMUM RATINGS Supply voltage V CC Max. voltage, logic and V input REF Operating temperature range Storage temperature range ELECTRICAL CHARACTERISTICS Parameter ZN448 Linearity error Differential linearity error Zero transition (00000000 00000001) Full-scale transition (11111110 11111111) ZN449 Linearity ...
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ELECTRICAL CHARACTERISTICS Parameter Clock On-chip clock frequency Clock frequency temperature coefficient Clock resistor Maximum external clock frequency Clock pulse width High level input voltage V IH Low level input voltage V IL High level input current I IH Low level ...
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ZN448/9 After the CONVERT input goes high again the MSB decision is made and the successive approximation routine runs to completion. The CONVERT pulse can be as short as 200ns; however the MSB must be allowed to settle for at ...
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If a free-running conversion is required, then the converter can be made to cycle by inverting the BUSY output and feeding it to WR. To ensure that the converter starts reliably after power initial start pulse is required. ...
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ZN448/9 (PIN 2) GROUND 500 20k 10k RD Fig.5 Data output Fig.6 Output enable/disable delays BITS 1-8 (PINS 11-18) ...
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BUSY OUTPUT The BUSY output, shown in Fig.7, utilises a passive pull-up for CMOS/TTL compatibility. This allows up to four BUSY outputs ON-CHIP CLOCK The on-chip clock operates with only a single external capacitor connected between pin 3 and ground, ...
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ZN448/9 1MHz 100kHz 10kHz 1kHz 10p ANALOG CIRCUITS D-A converter The converter is of the voltage switching type and uses ladder network as shown in Fig.10. Each element is connected to either transistor ...
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REFERENCE (a) Internal reference The internal reference is an active bandgap circuit which is equivalent to a 2.5V Zener diode with a very low slope impedance (Fig.11). A Resistor (R REF between pins 8 and 10. The recommended value of ...
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ZN448 Fig.13 Diode pump circuits to supply comparator tail current 10 +5V PIN PIN 6 4k PIN 5 R EXT I EXT V - Fig.12 Comparator equivalent circuit ...
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Several suitable circuits are shown in Fig.13. The principle of operation is the same in each case. Whilst the BUSY output is high, capacitor C1 is charged to about 4-4.5V. During a conversion the BUSY output goes low and the ...
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ZN448/9 ANALOG INPUT RANGES The basic connection of the ZN448/9 shown in Fig.15 has an analogue input range which, in some applications, REF IN may be made available from previous signal conditioning/ scaling circuits. Input voltage ranges ...
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UNIPOLAR OPERATION The general connection for unipolar operation is shown in Fig.16. The values of R and R are chosen so that the analog input ( full-scale. IN The resulting full-scale range is given ...
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ZN448 GAIN ADJUST R1 5k6 R2 8k2 +5V FULL-SCALE Unipolar adjustment prodedure (i) Apply continuous convert pulses at intervals long enough to allow a complete conversion and monitor the digital outputs. (ii) Apply full-scale minus 1.5LSB ...
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BIPOLAR OPERATION For bipolar operation the input to the ZN448/9 is offset by half full-scale by connecting a resistor R 3 (Fig.18). When A = -FS, V needs to be equal to zero When A = +FS, V ...
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ZN448 OFFSET ADJUST 13k 5k GAIN ADJUST 13k ±5VOLTS FULL SCALE Bipolar adjustment prodedure (i) Apply continuous SC pulses at intervals long enough to allow a complete conversion and monitor the digital outputs. (ii) Apply -(FS -0.5LSB) ...
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ZN448/9 17 ...
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