CS5526-BSZR Cirrus Logic Inc, CS5526-BSZR Datasheet - Page 8

• Manufacturer Part Number: CS5526-BSZR
• Description: IC 20-Bit Delta Sigma Multi-Range ADC
• Manufacturer: Cirrus Logic Inc

Specifications of CS5526-BSZR

• Number Of Bits: 20
• Data Interface: Serial
• Number Of Converters: 1
• Power Dissipation (max): 12.7mW
• Voltage Supply Source: Dual ±
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 598-1014 - EVAL BOARD FOR CS5526
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DETAILED DESCRIPTION
The CS5525 and CS5526 are 16-bit and 20-bit pin
compatible converters which include a chopper-
stabilized instrumentation amplifier input, and an
on-chip programmable gain amplifier. They are
both optimized for measuring low-level unipolar or
bipolar signals in process control and medical ap-
plications.
The CS5525/26 also include a fourth order delta-
sigma modulator, a calibration microcontroller,
eight digital filters, a 4-bit analog latch, and a serial
port. The digital filters provide any one of eight
different output update rates.
The CS5525/26 include a CPD (Charge Pump
Drive) output (shown in Figure 1). CPD provides a
negative bias voltage to the on-chip instrumenta-
tion amplifier when used with a combination of ex-
ternal diodes and capacitors. This enables the
CS5525/26 to measure negative voltages with re-
8
Figure 1. CS5525/26 Configured to use on-chip charge pump to supply NBV.
spect to ground, making the converters ideal for
thermocouple temperature measurements.
Theory of Operation
The CS5525/26 A/D converters are designed to op-
erate from a single +5 V analog supply and provide
several different input ranges. See the Analog
Characteristics section on page 3 for details.
Figure 1 illustrates the CS5525/26 connected to
generate their own negative bias supply using the
on-chip CPD (Charge Pump Drive). This enables
the CS5525/26 to measure ground referenced sig-
nals with magnitudes down to NBV (Negative Bias
Voltage, approximately -2.1 V in this example).
Figure 2 illustrates a charge pump circuit when the
converters are powered from a +3.0 V digital sup-
ply. Alternatively, the negative bias supply can be
generated from a negative supply voltage or a resis-
tive divider as illustrated in Figure 3.
CS5525 CS5526
DS202F5