Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
TDC1044AR4C Datasheet(PDF) 2 Page - Fairchild Semiconductor |
|
TDC1044AR4C Datasheet(HTML) 2 Page - Fairchild Semiconductor |
2 / 16 page TDC1044A PRODUCT SPECIFICATION 2 Functional Description General Information The TDC1044A has three functional sections: a comparator array, encoding logic, and an output register. The comparator array compares the input signal with 15 reference voltages to produce an N-of-15 thermometer code. All the comparators referred to voltages more positive than the input signal will be off, and those referred to voltages more negative than the input signal will be on. Encoding logic converts the N-of-15 code into binary or two’s complement coding and can invert either output code. This coding function is controlled by DC signals on pins NMINV and NLINV. The output register holds the output constant between updates. Power The TDC1044A operates from two power supply voltages, +5.0V and -5.2V. The return for ICC (the current drawn from the +5.0V supply) is DGND. The return for IEE (the current drawn from the -5.2V supply) is AGND. All power and ground pins must be connected. Reference The TDC1044A converts analog signals in the range VRB £ VIN £ VRB into digital form. VRB (the voltage applied to RB at the bottom of the reference resistor chain) and VRT (the voltage applied to RB at the top of the refer- ence resistor chain) should be between +0.1V and -1.1V. VRT should be more positive than VRB within that range. The voltage applied across the reference resistor chain (VRT – VRB) must be between 0.4V and 1.3V. Nominal voltages are VRT = 0.00V and VRB = -1.00V. These voltages may be varied dynamically up to 10MHz. Due to slight variation in the reference currents with clock and input signals, RT and RB should be low-impedance points. For cir- cuits in which the reference is not varied, a bypass capacitor to ground is recommended. If the reference inputs are varied dynamically (as in an Automatic Gain Control circuit), a low-impedance reference source is required. A reference middle, RM, is also provided; this may be used as an input to adjust the mid-scale point in order to improve integral linearity. This point may also be used as a tap to sup- ply a mid-scale voltage to offset the analog input. If VRM is used as an output, it must be connected to a high input impedance device which has small input current. Noise at this point may adversely affect the performance of this device. Controls Two function control pins, NMINV and NLINV, set the out- put format to be either straight binary or offset two’s comple- ment, in either true or inverted sense, according to Table 1. These pins are active LOW as signified by the prefix "N" in the signal name. They may be tied to VCC for a logic "1" and DGND for a logic "0." NMINV controls the MSB, D1; NLINV controls the three LSBs: D2, D3 and D4. Convert The TDC1044A requires a CONVert (CONV) signal. A sam- ple is taken (the comparators are latched) within tSTO after a rising edge of CONV. The coded result is translated to the output latches on the next rising edge. The outputs hold the previous data a minimum time (tHO) after the rising edge of the CONV signal. New data becomes valid after a maximum delay time, tD. Analog Input The TDC1044A uses latching comparators which cause the input impedance to vary slightly with the signal level. For optimal performance, the source impedance of the driving circuit must less than 25 Ohms. Within the range of VEE to +0.5V, the input signal will not damage the device. If the input signal is at a voltage between VRT and VRB, the output will be a binary code between 0 and 15 inclusive. A signal outside this range will indicate either full-scale positive or full-scale negative, depending on whether the signal is off- scale in the positive or negative direction. Outputs TDC1044A outputs are TTL compatible, and capable of driving four low-power Schottky TTL (54/74 LS) unit loads. The outputs hold the previous data a minimum time (tHO) after the rising edge of the CONV signal. Data becomes valid after a maximum delay time (tD) after the rising edge of CONV. For optimum performance, 2.2 kOhm pull-up resistors are recommended. No Connects Pin 3 of the TDC1044A is labeled No Connect (NC), and has no connection to the chip. Connect this pin to AGND for best noise performance. |
Número de pieza similar - TDC1044AR4C |
|
Descripción similar - TDC1044AR4C |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes 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 |