Electronic Components Datasheet Search |
|
ZN448E Datasheet(PDF) 5 Page - List of Unclassifed Manufacturers |
|
ZN448E Datasheet(HTML) 5 Page - List of Unclassifed Manufacturers |
5 / 18 page ZN448/9 5 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- up an initial start pulse is required. This can be ensured by using a NOR gate instead of an inverter and feeding it with a positive-going pulse which can be derived from a simple RC network that gives a single pulse when power is applied, as shown in Fig.4a. The ADC will complete a conversion on every eighth clock pulse, with the BUSY output going high for a period determined by the propagation delay of the NOR gate, during which time the data can be stored in a latch. The time available for storing data can be increased by inserting delays into the inverter path. A timing diagram for the continuous conversion mode is shown in Fig.3b. As the BUSY output uses a passive pull-up the rise time of this output depends on the RC time constant of the pull-up resistor and load capacitance. In the continuous conversion mode the use of a 4k7 external pull-up resistor is recommended to reduce the risetime and ensure that a logic 1 level is reached. Fig.4b Timing for continuous conversion DATA OUTPUTS The data outputs are provided with three-state buffers to allow connection to a common data bus. An equivalent circuit is shown in Fig.5. Whilst the RD input is high both output transistors are turned off and the ZN448/9 presents only a high impedance load to the bus. When RD is low the data outputs will assume the logic states present at the outputs of the successive register. A test circuit and timing diagram for the output enable/disable delays are given in Fig.6. Fig.4a Circuit for continuous conversion |
Similar Part No. - ZN448E |
|
Similar Description - ZN448E |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |