ADS7842E/1KG4 - 12-Bit 4-Ch 200kHz SAR ADC | Texas Instruments
Référence : ADS7842E/1KG4 ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $9.45 | $9,45 |
| 10 | $8.62 | $86,20 |
| 100 | $7.3 | $730,00 |
| 500 | $6.15 | $3 075,00 |
| 1 000 | $5.2 | $5 200,00 |
ADS7842E/1KG4 Présentation
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary-search algorithm against an internal capacitive DAC to resolve one bit per clock cycle. SAR ADCs sit in the broader hierarchy of ADCs (successive approximation, sigma-delta, pipeline, flash), and within mixed-signal data acquisition ICs. SAR converters are favored where low latency, deterministic throughput, and moderate resolution (8-16 bit) matter, such as in multiplexed sensor front ends and process control loops.
Key features include a 200 kHz maximum sample rate, 4 single-ended analog input channels with internal multiplexer, 12-bit no-missing-codes resolution, ±1 LSB max INL, ±1 LSB max DNL, and a parallel interface that drops directly onto 8-/16-bit microprocessor data buses. The device accepts a 2.7 V to 5.5 V analog supply and digital supply, supports an external reference, and includes a power-down mode that drops quiescent current to microamp levels for battery-powered designs.
Architecturally, the ADS7842 uses a charge-redistribution DAC switched by the SAR logic clocked from the external oscillator applied to the CLK pin. The sample-and-hold front end captures the input on the rising edge of CS, and conversion completes within 16 clock cycles. Parallel 3-state drivers allow the data bus to be shared with other peripherals without external buffers.
Typical applications include industrial process control (multi-loop PLC analog front ends), data acquisition systems, multi-channel instrumentation, medical patient monitoring front ends, and battery management analog input aggregation. The 4-channel input count makes the part cost-effective when 2-4 sensors must be read through one ADC.
Designers should size the external reference decoupling carefully (typically 10 uF tantalum in parallel with 0.1 uF ceramic) and ensure the CLK pin is driven with a clean 50%-duty-cycle waveform between 0.1 MHz and 2.5 MHz. Avoid routing digital outputs directly beneath the analog input traces to minimize digital-to-analog coupling into the next conversion cycle.
Alternatives de remplacement direct pour ADS7842E/1KG4 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ADS7842E/1KG4 (même facteur de forme et même empreinte) — différant par Package, Power Dissipation, Resolution, RoHS Status.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ADS7842E/1K
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADS7842EB/1KG4
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADS7842E
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADS7842E/2K
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADS7842E/1K
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADS7824UB/1KG4
✅ Remplacement direct✓ En stock
$9.4 / unité
Voir la fiche technique →ADS7842E/1KG4 Valeurs maximales et caractéristiques électriques
| Résolution | 12 bit |
| Number of Channels | 4 single-ended |
| Architecture | SAR (Successive Approximation Register) |
| Sample Rate | 200 kSPS (maximum) |
| Input Type | Single-ended analog |
| Linearity Error (Max) | 0.0488% (1 LSB) |
| Output Interface | Parallel, 3-state |
| Reference Input | External, 3 V or 5 V typical |
| Analog Supply Voltage | 3 V or 5 V |
| Digital Supply Voltage | 3 V or 5 V |
| Power Dissipation | 2 mW (typical at rated throughput) |
| Température de fonctionnement | -40 C to +85 C (industrial) |
| Boîtier | 28-pin SSOP (DB) |
| Type de montage | Surface Mount |
| Niveau MSL | 2 (1 year) |
| Statut RoHS | Compliant (Pb-free, G4 suffix) |
| Lead-Free | Yes (G4 suffix) |
Configuration des broches de ADS7842E/1KG4
| Broche 1 | VCC — Analog supply voltage (3 V or 5 V) |
| Broche 2 | CH0 — Analog input channel 0 |
| Broche 3 | CH1 — Analog input channel 1 |
| Broche 4 | CH2 — Analog input channel 2 |
| Broche 5 | CH3 — Analog input channel 3 |
| Broche 6 | REF — External reference voltage input |
| Broche 7 | AGND — Analog ground |
| Broche 8 | CLK — External oscillator / conversion clock input |
| Broche 9 | CS — Active-low chip select / conversion start |
| Broche 10 | BUSY — Active-high conversion-in-progress flag |
| Broche 11 | RD — Active-low parallel read strobe |
| Broche 12 | D11 (MSB) — Parallel data output bit 11 |
| Broche 13 | D10 — Parallel data output bit 10 |
| Broche 14 | D9 — Parallel data output bit 9 |
| Broche 15 | D8 — Parallel data output bit 8 |
| Broche 16 | D7 — Parallel data output bit 7 |
| Broche 17 | D6 — Parallel data output bit 6 |
| Broche 18 | D5 — Parallel data output bit 5 |
| Broche 19 | D4 — Parallel data output bit 4 |
| Broche 20 | D3 — Parallel data output bit 3 |
| Broche 21 | D2 — Parallel data output bit 2 |
| Broche 22 | D1 — Parallel data output bit 1 |
| Broche 23 | D0 (LSB) — Parallel data output bit 0 |
| Broche 24 | DGND — Digital ground |
| Broche 25 | VDD — Digital supply voltage (3 V or 5 V) |
| Broche 26 | OE — Output enable for 3-state parallel drivers |
| Broche 27 | NC — Not connected (per datasheet) |
| Broche 28 | NC — Not connected (per datasheet) |
Applications typiques
ADS7842E/1KG4 convient pour 6 applications: Industrial Process Control / PLC Analog Front End, Multi-Channel Data Acquisition Systems, Medical Patient Monitoring Front End, Battery Management Analog Input Aggregation, Multi-Channel Instrumentation, HMI Touch Screen / Position Sensing Aggregation.
Industrial Process Control / PLC Analog Front End
The ADS7842E/1KG4 is well suited to industrial process control analog front ends because it integrates a 12-bit SAR core with a built-in 4-channel analog multiplexer, allowing one IC to digitize up to four 4-20 mA-conditioned or 0-10 V sensor signals in a PLC chassis. At 200 kSPS the part easily sequences through four channels at the typical PLC scan rates of 1-10 kHz per channel, while the 0.0488% (±1 LSB) linearity error keeps process-loop accuracy within the budget for most closed-loop control designs. The 28-pin SSOP (DB) package fits the standard PLC board footprint, and the parallel 3-state interface connects directly to a microcontroller or DSP data bus without external latches.
Recommandé
Multi-Channel Data Acquisition Systems
In multi-channel data acquisition systems, the ADS7842E/1KG4's 4-channel input mux combined with 200 kSPS throughput allows designers to digitize 4 sensors in sequence with deterministic conversion latency - critical for synchronized sampling. SAR architecture avoids the latency of sigma-delta ADCs, which is important when the downstream DSP or FPGA must respond within microseconds. The 12-bit resolution is appropriate for vibration, strain-gauge, and temperature front ends where 0.0244% (1/2 LSB) effective precision is sufficient. The parallel output bus also simplifies integration with FPGA-based acquisition cards.
Recommandé
Medical Patient Monitoring Front End
The ADS7842E/1KG4 serves medical patient-monitoring analog front ends where 4 channels of ECG, SpO2, respiration, or temperature signals need to be digitized from a single IC. SAR architecture provides deterministic conversion latency, which is essential for synchronized ECG sampling and avoids the group delay of sigma-delta converters. The 200 kSPS throughput easily supports 4 channels at 1 kHz each, leaving headroom for oversampling to improve effective resolution. The industrial -40 C to +85 C operating range and Pb-free G4 assembly match the medical-device regulatory and environmental requirements, and the SSOP-28 footprint is widely accepted in IEC 60601-compliant layouts.
Recommandé
Battery Management Analog Input Aggregation
In battery management systems, the ADS7842E/1KG4 aggregates multiple analog inputs - cell voltage, pack current, and temperature - through its 4-channel input mux into a single MCU-readable data stream. The 2 mW typical power dissipation at rated throughput is low enough for always-on monitoring without excessively draining the battery, and the integrated power-down mode drops quiescent current to microamp levels between conversions. The 3 V or 5 V supply flexibility allows direct connection to single-cell Li-ion rails (with LDO) or to a 5 V system rail typical of e-bike and small-EV battery packs.
Recommandé
Multi-Channel Instrumentation
Bench-top and portable instrumentation - including digital multimeters, source-measure units, and laboratory data loggers - can use the ADS7842E/1KG4 to digitize four measurement ranges in sequence. The 12-bit resolution handles most general-purpose instrumentation tasks, and the external reference input lets designers share a precision 5 V reference across the entire instrument for ratiometric accuracy. The parallel interface simplifies connection to legacy microcontrollers used in low-cost portable instruments, and the SSOP-28 industrial-grade package fits both handheld and bench-form-factor designs.
Recommandé
HMI Touch Screen / Position Sensing Aggregation
In human-machine interface (HMI) panels, the ADS7842E/1KG4 aggregates analog signals from resistive touch screens, rotary encoders, and analog front-end sensors before forwarding the data to the host processor. Its 4 single-ended channels and 200 kSPS throughput allow continuous polling of multiple analog inputs without missing touch events. The parallel 3-state outputs integrate with 8-bit and 16-bit microcontroller buses common in industrial HMI controllers, and the SSOP-28 footprint is compatible with the same PCB layout typically used by touchscreen controller daughter boards.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ADS7842E/1KG4 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ADS7842E/1K | ADS7842EB/1KG4 | ADS7824UB/1KG4 | ADS7825UE4 |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-pin SSOP (DB) | 28-pin SSOP (DB) - same | 28-pin SSOP (DB) - same | 28-pin SSOP (DB) - same | 28-pin SSOP (DB) - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 16 bit |
| Number of Channels | 4 single-ended | 4 single-ended | 4 single-ended | 4 single-ended | 4 single-ended |
| Output Interface | Parallel, 3-state | Parallel, 3-state | Parallel, 3-state | Parallel | Parallel |
| Supply Voltage | 3 V or 5 V | 3 V or 5 V | 3 V or 5 V | 5 V | 5 V |
| RoHS / Pb-Free | RoHS / Pb-free (G4 suffix) | Non-G4 (leaded standard) | RoHS / Pb-free (G4 suffix) | RoHS / Pb-free (G4 suffix) | RoHS (E4 suffix) |
Principaux différenciateurs
- Wide cross-brand drop-in availability within TI ADS7842 family (vs ADS7842E/1K)
- Higher-grade screened variant available for precision applications (vs ADS7842EB/1KG4)
- 4-channel integration versus standalone ADCs (vs ADS7822PBG4 (lower-channel-count family cousin))
- 200 kSPS deterministic SAR throughput for time-critical control (vs Sigma-delta ADC family alternatives (e.g. ADS1100))
Notes de conception
Place the external reference decoupling capacitors as close as possible to the REF pin - typically a 10 uF tantalum in parallel with a 0.1 uF ceramic. Route the AGND and DGND grounds as separate traces that join only at the ADC GND pin to avoid digital return currents coupling into the analog sample. Keep digital output traces (D0-D11, BUSY, RD) short and routed away from CH0-CH3 analog input traces and the REF pin trace to minimize digital-to-analog feedthrough that can corrupt the next conversion cycle.
Decouple both VCC (analog) and VDD (digital) with a 0.1 uF ceramic capacitor placed within 5 mm of each supply pin, and add a bulk 10 uF tantalum on each rail. The ADS7842E/1KG4 draws approximately 2 mW at rated throughput; ensure the upstream LDO or switching regulator has adequate headroom and low ripple (<5 mV pk-pk) so that supply noise does not fold back into the conversion. The integrated power-down mode can be used between bursts of conversions to drop quiescent current to microamp levels in battery-powered designs.
The CLK pin must be driven with a clean 50%-duty-cycle clock between approximately 0.1 MHz and 2.5 MHz; excessive jitter or slow rise times will degrade SAR linearity. Do not leave CS floating - it must be pulled high between conversions to avoid spurious starts. When reading parallel data, drive OE (output enable) low before asserting RD, and deassert OE after RD goes high to avoid bus contention with other peripherals. Finally, ensure the external reference voltage settles within 1 LSB accuracy before the next conversion is initiated, or use the BUSY flag as the trigger to read valid output data.
At 2 mW typical dissipation the ADS7842E/1KG4 does not require a heatsink, but its 28-pin SSOP package has limited copper-down thermal coupling. Estimated: assuming theta_JA of ~95 C/W for SSOP-28 on a 1-oz 2-layer board, a 2 mW dissipation yields a junction temperature rise of less than 0.2 C above ambient - well within the -40 C to +85 C operating range. For higher ambient temperatures above 70 C or for boards with poor copper pour, consider placing a copper flood under the exposed SSOP leads to reduce theta_JA further.
Informations de conformité
RoHS compliant per G4 suffix in TI part number and distributor listings. Reach compliance assumed per TI standard material declaration; AEC-Q100 not applicable (industrial grade, -40 C to +85 C). Conflict-minerals compliance per TI standard statement; halogen-free status requires explicit confirmation against the latest TI material declaration if required.
