ADC10061 National Semiconductor Corporation, ADC10061 Datasheet - Page 8

• Manufacturer Part Number: ADC10061
• Description: ADC10061 - 10-Bit 600 NS A/D Converter With Input Multiplexer And Sample/Hold, Package: Soic Wide, Pin Nb=20
• Manufacturer: National Semiconductor Corporation

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Timing Diagrams
Functional Description
The ADC10061, ADC10062 and ADC10064 digitize an ana-
log input signal to 10 bits accuracy by performing two
lower-resolution “flash” conversions. The first flash conver-
sion provides the six most significant bits (MSBs) of data,
and the second flash conversion provides the four least
significant bits LSBs).
FIGURE 1. Mode 1. The conversion time (t
FIGURE 2. Mode 2 (RD Mode). The conversion time (t
sampling time and is determined by the internal timer.
8
Figure 3 is a simplified block diagram of the converter. Near
the center of the diagram is a string of resistors. At the
bottom of the string of resistors are 16 resistors, each of
which has a value 1/1024 the resistance of the whole resistor
string. These lower 16 resistors (the LSB Ladder ) therefore
have a voltage drop of 16/1024, or 1/64 of the total reference
voltage (V
resistor string is made up of eight groups of eight resistors
connected in series. These comprise the MSB Ladder. Each
CONV
) is set by the internal timer.
REF+
− V
CRD
REF−
) includes the
) across them. The remainder of the
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