Generic precision ADC packages connected to sensor signal paths for ADS1220 and ADS1248 comparison

ADS1220IPWR vs ADS1248IPWR: Choosing a 24-Bit Sensor ADC

ADS1220IPWR and ADS1248IPWR are Texas Instruments 24-bit delta-sigma ADCs designed for precision sensor measurement. Both support data rates up to 2 kSPS, an SPI-compatible interface, a programmable-gain amplifier up to 128, an internal 2.048 V reference and dual programmable excitation-current sources. Those similarities can make them appear interchangeable in a parametric search.

They are not pin-compatible equivalents. ADS1220IPWR is a 16-pin TSSOP device with four analog inputs and a 2.3 V to 5.5 V supply range. ADS1248IPWR is a 28-pin TSSOP device with eight analog inputs, more GPIO and sensor-monitoring resources, and 2.7 V to 5.25 V unipolar analog and digital supply ranges. Their pinouts, register maps and feature routing differ, so moving between them is a board-and-firmware redesign.

Quick comparison

Parameter ADS1220IPWR ADS1248IPWR
Resolution 24 bit 24 bit
Maximum data rate 2 kSPS 2 kSPS
Analog inputs 4 inputs / up to 2 differential pairs; single-ended measurement bypasses the PGA and uses gain 1, 2 or 4 8 inputs / up to 4 differential pairs
PGA gains 1 to 128 1 to 128
Interface SPI-compatible, mode 1 specified SPI-compatible, mode 1 specified
Internal reference 2.048 V, 5 ppm/°C typical drift 2.048 V; 10 ppm/°C max (+25°C to +105°C); 15 ppm/°C max (–40°C to +105°C)
Excitation currents Two, 10 µA to 1.5 mA Two, 50 µA to 1.5 mA
Unipolar supply 2.3 V to 5.5 V 2.7 V to 5.25 V
Package for IPWR TSSOP-16, tape-and-reel TSSOP-28, tape-and-reel
Operating temperature –40°C to +125°C –40°C to +125°C
Notable integration Low-side switch, burn-out detection, analog-supply/reference monitoring, small footprint, low-power modes Up to eight multiplexed GPIOs, broader system monitoring, self/system calibration, dedicated IEXC pins

The reference-drift numbers use different statistical labels—typical for ADS1220 and maximum for ADS1248—so they should not be treated as an apples-to-apples guarantee. For ADS1248, TI specifies 10 ppm/°C maximum from +25°C to +105°C and 15 ppm/°C maximum from –40°C to +105°C. The device can operate to +125°C, but those reference-drift limits should not be presented as guaranteed across the full –40°C to +125°C operating range.

When ADS1220IPWR is the better starting point

ADS1220IPWR suits designs that need up to two differential or four single-ended sensor inputs and place a premium on board area and power. TI offers it in a 16-pin TSSOP for the IPWR orderable part. Its supply range reaches down to 2.3 V and its integrated excitation sources include 10 µA, 50 µA, 100 µA, 250 µA, 500 µA, 1 mA and 1.5 mA settings.

The device includes a flexible input multiplexer, PGA, internal oscillator, temperature sensor, low-side power switch and two IDACs. It also provides 10 µA burn-out sources for open- or shorted-sensor checks, analog-supply monitoring, external-reference monitoring and an internal shorted-input path for offset checks. TI specifies simultaneous 50 Hz and 60 Hz rejection at 20 SPS. ADS1220 can also use bipolar analog supplies around ±2.5 V within the datasheet limits. These features make it useful for compact RTD, thermocouple, thermistor and bridge-sensor front ends.

“24 bit” is the converter resolution, not a promise of 24 noise-free bits in a finished product. Effective resolution depends on data rate, gain, reference, source impedance, layout, filtering and environmental noise. Use TI’s noise tables for the chosen mode, then build a complete error budget.

When ADS1248IPWR is the better starting point

ADS1248IPWR is the more highly pinned option. Its eight-input multiplexer supports four differential input pairs, and TI provides up to eight multiplexed GPIO functions. GPIO0 and GPIO1 share reference pins, while GPIO2 through GPIO7 share analog-input pins, so using a GPIO can consume another function. Compared with ADS1220, ADS1248 adds broader system-monitoring resources, digital-supply monitoring, self and system calibration, and dedicated IEXC1 and IEXC2 output pins in addition to routing excitation current to analog inputs.

That integration can simplify multi-sensor equipment. For example, a system measuring several RTDs or combining thermocouple and cold-junction measurements may value the extra inputs and routing flexibility more than the smaller package.

The ADS1248’s IDAC settings begin at 50 µA, not the 10 µA minimum available on ADS1220. Its unipolar analog and digital supplies begin at 2.7 V and top out at 5.25 V. Like ADS1220, ADS1248 also supports bipolar analog operation around ±2.5 V, subject to the exact datasheet limits, supply sequencing and input common-mode requirements.

Why migration requires redesign

The package difference is immediate: TSSOP-16 versus TSSOP-28, with different body sizes and pin assignments. A PCB footprint change is mandatory. Firmware must also be rewritten or adapted because configuration-register layouts and command behavior are not the same.

Sensor routing may change as well. The ADS1248 exposes dedicated excitation-current pins and more reference and GPIO resources; the ADS1220 uses a smaller pin budget and a different internal routing architecture. Recalculate IDAC compliance voltage, reference-resistor dissipation, input common mode, PGA headroom and anti-alias filtering.

Power architecture is another migration gate. A 2.5 V unipolar system that is within the ADS1220 range is below the ADS1248’s 2.7 V unipolar minimum. Both devices can also use bipolar analog supplies around ±2.5 V, but their recommended rail limits and sequencing requirements must be checked separately. Do not treat an absolute-maximum rail as a recommended operating point.

Finally, compare timing at the command level. Both devices reach 2 kSPS and both offer single-cycle settling behavior, but data-ready timing, startup, calibration, multiplexer switching and digital-filter configuration must be taken from the exact device datasheet.

For broader supplier, traceability, alternate-part and approval controls, use our electronic component BOM sourcing process alongside the device-specific checks below.

Procurement verification checklist

  • Match the exact MPN and suffix: ADS1220IPWR or ADS1248IPWR.
  • Confirm TSSOP-16 versus TSSOP-28 and the matching PCB revision.
  • Count required single-ended and differential sensor channels.
  • Verify analog and digital rails across tolerance and startup sequencing.
  • Record PGA gain, data rate, filter mode and required 50/60 Hz rejection.
  • Confirm the selected IDAC current exists on the target device.
  • Check IDAC routing, compliance voltage and reference-resistor power.
  • Review internal/external reference selection and reference drift in the error budget.
  • Verify firmware register map, SPI timing, DRDY behavior and calibration flow.
  • Validate noise, offset, gain, linearity and temperature performance in the complete signal chain.

FAQ

Are ADS1220IPWR and ADS1248IPWR pin-compatible?
No. ADS1220IPWR is TSSOP-16 and ADS1248IPWR is TSSOP-28, with different pinouts.

Do both provide 24-bit conversion at 2 kSPS?
Yes, both are 24-bit delta-sigma ADCs with data rates up to 2 kSPS. Achievable noise-free resolution depends on configuration and system design.

Which has more analog channels?
ADS1248 has eight analog inputs; ADS1220 has four.

Which supports a lower supply?
ADS1220’s unipolar analog and digital range starts at 2.3 V. ADS1248’s corresponding published range starts at 2.7 V.

Can existing ADS1248 firmware control ADS1220?
Do not assume so. The register maps, pin resources and feature routing differ.

Engineering boundary

This comparison is not a direct-replacement declaration. Select and qualify the ADC using the latest TI datasheet, sensor topology, source impedance, noise and accuracy budget, power architecture, schematic, PCB layout and production calibration strategy.

Related catalog pages

Review the exact catalog entries for ADS1220IPWR and ADS1248IPWR, then send the required MPN and BOM context through the contact page.

Official references

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