Part A
AD7228ACRZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 2789 個数
- Package
- SOIC-24
- Series
- データ取得 - デジタル/アナログコンバータ (DAC)
Replacement verdict
Not a drop-in replacement
The AD7228ACRZ and AD7225LR are not drop-in replacements for one another. Although both are octal 8-bit voltage-output DACs from Analog Devices, they differ in output amplifier architecture, reference input configuration, package footprint, and interface timing, so a direct board-level substitution is not possible without design changes.
Different output amplifier type
Different reference input configuration
Different package footprint
Different interface timing
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7228ACRZ | AD7225LR | Why it matters |
|---|---|---|---|
| Number of DAC Channels | 8 | 4 | Determines how many independent analog outputs the device can drive; a direct functional substitutability constraint. |
| DAC Architecture / Resolution | 8-bit voltage-output DAC | 8-bit voltage-output DAC | Both are 8-bit voltage-output DACs, so resolution and output type match, but channel count differs. |
| Output Voltage Range | 0 V to VREF (unipolar); VREF to GND (bipolar option) | 0 V to VREF (unipolar); VREF to GND (bipolar option) | Defines the analog output span; matching ranges allow similar signal-chain compatibility. |
| Reference Input | External VREF | External VREF | Both require an external reference, so system reference design can be reused. |
| Digital Interface | Parallel, microprocessor-compatible | Parallel, microprocessor-compatible | Interface compatibility affects whether the part can drop into an existing bus without glue logic. |
| Supply Voltage | +12 V to +15 V (VDD), -12 V to -15 V (VSS) | +12 V to +15 V (VDD), -12 V to -15 V (VSS) | Power rail requirements must match the host system for direct substitution. |
| Package | 28-lead SOIC (R-28) | 24-lead SOIC (R-24) | Different package footprints prevent pin-for-pin board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | Matching temperature grades ensure equivalent environmental robustness. |
| Settling Time | ~5 µs (to ±1/2 LSB) | ~5 µs (to ±1/2 LSB) | Similar settling times mean comparable dynamic performance in control loops. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7228ACRZ | AD7225LR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 8 | 8 |
| Number of D/A Converters | 8 | 4 |
| Settling Time | 5µs, 7µs | 4µs |
| Output Type | Voltage - Buffered | Voltage - Buffered |
| Differential Output | No | No |
| Data Interface | Parallel | Parallel |
| Reference Type | External | External |
| Voltage - Supply, Analog | 10.8V ~ 16.5V, ±5V | 11.4V ~ 16.5V, -5V |
| Voltage - Supply, Digital | 13.5V ~ 16.5V | 14.25V ~ 15.75V |
| INL / DNL(LSB) | ±0.5 (Max), ±1 (Max) | ±0.5 (Max), ±1 (Max) |
| Architecture | R-2R | R-2R |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the primary functional differences between the AD7228ACRZ and the AD7225LR?
The AD7228ACRZ is an octal 8-bit voltage-output digital-to-analog converter (DAC) with eight independent DACs, while the AD7225LR is a quad 8-bit voltage-output DAC with four independent DACs. Both are manufactured by Analog Devices and operate from a single +5 V to +15 V supply (with the AD7228 also supporting dual supplies), but the AD7228ACRZ provides twice the channel count of the AD7225LR.
Are the AD7228ACRZ and AD7225LR pin-compatible or package-compatible?
No. The AD7228ACRZ is supplied in a 24-lead SOIC (R-24) package, while the AD7225LR is supplied in a 24-lead SOIC (R-24) package as well, but the pin functions differ because the AD7228 provides eight DAC outputs and the AD7225 provides four. The two devices are not drop-in replacements and require separate PCB layouts.
What are the resolution and accuracy specifications of each device?
Both the AD7228ACRZ and the AD7225LR are 8-bit resolution DACs. The AD7228ACRZ is specified with ±1 LSB integral nonlinearity (INL) and ±1 LSB differential nonlinearity (DNL) over its operating temperature range. The AD7225LR is specified with ±1/2 LSB INL and ±1 LSB DNL. Designers should consult the respective Analog Devices datasheets for the exact grade-specific limits.
What are the supply voltage and reference requirements for these DACs?
The AD7228ACRZ operates from a single +5 V to +15 V supply or dual ±5 V to ±15 V supplies, and requires an external voltage reference. The AD7225LR operates from a single +5 V to +15 V supply and also requires an external reference. Both devices accept a reference input that sets the full-scale output range, so the reference source must be selected to match the desired output span.
What digital interface do the AD7228ACRZ and AD7225LR use?
Both devices use a parallel microprocessor-compatible digital interface. The AD7228ACRZ has an 8-bit data bus with address decoding for eight DAC latches, while the AD7225LR has an 8-bit data bus with 2-bit address decoding for four DAC latches. Both include WR and chip-select control lines for direct connection to standard microprocessors.
What are the operating temperature ranges for the AD7228ACRZ and AD7225LR?
The AD7228ACRZ is specified for the commercial temperature range of 0°C to +70°C. The AD7225LR is specified for the industrial temperature range of -40°C to +85°C. The suffix letters in each part number indicate the grade and temperature range, so designers should confirm the exact ordering code against the Analog Devices datasheet.
Can the AD7225LR be used as a direct replacement for the AD7228ACRZ in an existing design?
No. Although both are 8-bit voltage-output DACs from Analog Devices, the AD7225LR provides only four DAC channels versus eight on the AD7228ACRZ, and the pin assignments and package wiring differ. A direct substitution would leave four DAC channels unpopulated and would not match the existing PCB footprint, so a redesign is required.
Which device is better suited for applications requiring more analog output channels?
The AD7228ACRZ is better suited for higher-channel-count applications because it integrates eight 8-bit DACs in a single package, reducing board space and component count compared with using two AD7225LR devices. The AD7225LR is preferable when only four channels are needed and lower per-channel cost or a smaller functional block is desired.