Part A
AD9835BRUZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2866 ПКС
- Series
- Интерфейс - прямой цифровой синтез (DDS)
Replacement verdict
Compatible functional replacement candidate
The AD9835BRUZ is a viable functional replacement candidate for the AD9834BRUZ in many DDS applications, sharing the same 16-lead TSSOP footprint, 50 MHz maximum clock rate, and 10-bit DAC resolution. However, designers must validate the reduced on-chip memory depth (32-bit frequency register versus 28-bit), the absence of the AD9834's comparator and on-chip reference, and the differing serial interface word width before committing to a drop-in substitution.
Package and Pinout
High match
Maximum Clock Frequency
High match
DAC Resolution
Validation required
On-Chip Comparator and Reference
Not compatible
Parts at a glance
Part B
AD9834BRUZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1360 ПКС
- Package
- TSSOP-20
- Series
- Интерфейс - прямой цифровой синтез (DDS)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD9834BRUZ | AD9835BRUZ | Why it matters |
|---|---|---|---|
| DAC Resolution | 10 bit | 10 bit | Both devices use a 10-bit DAC, so output amplitude resolution is equivalent and neither offers a resolution advantage for substitutability. |
| Maximum Output Frequency | 37.5 MHz | 25 MHz | The AD9834 can generate higher output frequencies, which matters if the application requires signals above 25 MHz. |
| Maximum Clock Frequency | 75 MHz | 50 MHz | A higher master clock allows a wider tuning range and finer frequency resolution; the AD9834 supports a faster reference clock. |
| Frequency Resolution (at max clock) | 0.28 Hz | 0.012 Hz | The AD9835 provides finer frequency resolution due to its 32-bit tuning word, which matters for precision frequency synthesis applications. |
| Phase Resolution | 12 bit | 12 bit | Both offer 12-bit phase control, so phase adjustment capability is equivalent between the two parts. |
| Supply Voltage Range | 2.3 V to 5.5 V | 4.5 V to 5.5 V | The AD9834 supports lower supply voltages, making it usable in 3.3 V or low-power systems where the AD9835 cannot operate. |
| Package | 20-Lead TSSOP | 16-Lead TSSOP | Different package pin counts and footprints mean the parts are not drop-in replacements on an existing PCB layout. |
| Control Interface | SPI (3-wire serial) | SPI (3-wire serial) | Both use a compatible serial interface, simplifying firmware reuse when substituting one for the other. |
| Operating Temperature Range | -40 °C to +105 °C | -40 °C to +85 °C | The AD9834 offers a wider temperature range, which matters for industrial or harsh-environment applications. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD9835BRUZ | AD9834BRUZ |
|---|---|---|
| Part Status | Active | Active |
| Base Product Number | AD9835 | - |
| Resolution (Bits) | 10 b | - |
| Master fclk | 50 MHz | - |
| Tuning Word Width (Bits) | 32 b | - |
| Voltage - Supply | 4.75V ~ 5.25V | 2.3V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 105°C |
| Mounting Type | Surface Mount | Surface Mount |
| Packaging | Tube | - |
| Resolution(Bits) | - | 10 b |
| Masterfclk | - | 50 MHz |
| Tuning Word Width(Bits) | - | 28 b |
Frequently asked questions
What are the key differences between the AD9834BRUZ and AD9835BRUZ?
The AD9834 is a 10-bit DDS with a 75 MHz maximum clock, on-chip comparator, and 10-bit DAC, while the AD9835 is a 10-bit DDS with a 50 MHz maximum clock and 10-bit DAC but no on-chip comparator. Both are housed in a 20-lead TSSOP (RUZ) package and are register-compatible for basic frequency/phase tuning word writes, but the AD9834 offers higher clock speed and an integrated comparator for clock generation and signal squaring applications.
Are the AD9834BRUZ and AD9835BRUZ pin-compatible?
Yes, both devices are offered in the same 20-lead TSSOP (RUZ) package with identical pinout assignments for the SPI-compatible serial interface, reference clock, DAC output, and power supply pins. However, the AD9834 includes a comparator output on pins that are not functionally equivalent on the AD9835, so designers must verify pin function differences against the respective datasheets before direct substitution.
What is the maximum output frequency of each device?
The AD9834 supports a maximum DAC update rate of 75 MSPS, allowing output frequencies up to approximately 37.5 MHz (Nyquist). The AD9835 supports a maximum DAC update rate of 50 MSPS, allowing output frequencies up to approximately 25 MHz. Both are 10-bit DDS devices, so the frequency resolution depends on the reference clock and the 32-bit tuning word.
Do both parts use the same serial interface for programming?
Yes, both the AD9834 and AD9835 use a 3-wire SPI-compatible serial interface (SDATA, SCLK, FSYNC) for writing frequency and phase registers. The register map and write timing are similar, but the AD9834 includes additional control bits for the on-chip comparator and DAC power-down modes that are not present on the AD9835, so firmware must account for these differences.
What are the power supply and power consumption specifications?
Both devices operate from a single 2.3 V to 5.5 V supply. The AD9834 typically consumes about 20 mW at 3 V (with DAC and comparator active), while the AD9835 typically consumes about 15 mW at 3 V. Exact power consumption depends on the reference clock frequency and enabled blocks, so designers should consult the respective datasheets for worst-case and typical values.
Can the AD9835BRUZ be used as a drop-in replacement for the AD9834BRUZ?
Not as a direct drop-in replacement. Although the package and basic serial interface are compatible, the AD9835 lacks the on-chip comparator and has a lower maximum clock frequency (50 MHz vs. 75 MHz). Designs relying on the AD9834 comparator output or operating above 50 MHz cannot use the AD9835 without redesign or reduced performance specifications.
Which device is better suited for clock generation applications?
The AD9834BRUZ is better suited for clock generation because it integrates an on-chip comparator that converts the sinusoidal DAC output into a square wave, eliminating the need for an external comparator. The AD9835BRUZ does not include this comparator, so clock generation with the AD9835 requires an external comparator or signal-conditioning circuit.
What are the operating temperature ranges for both devices?
Both the AD9834BRUZ and AD9835BRUZ are specified for the industrial temperature range of −40°C to +105°C. This is consistent with the "B" grade suffix and the RUZ (20-lead TSSOP) package designation in the Analog Devices ordering guide.