LT1790BCS6-5 - 5V Micropower SOT-23 Voltage Reference | Analog Devices
MPN: LT1790BCS6-5 ✓ Hoạt độngLT1790BCS6-5 Tóm tắt
A voltage reference IC is a precision circuit that produces a stable, temperature-independent DC voltage used as a calibration anchor for ADCs, DACs, power-supply monitors, and sensor signal-conditioning paths. Within the power-management hierarchy, references sit alongside voltage regulators and supervisors, providing the absolute voltage standard against which other rails are measured. The LT1790 family combines a buried-Zener or bandgap-style core with curvature compensation and trimmed precision thin-film resistors to deliver low drift, low noise, and very low quiescent current in a footprint compatible with portable and space-constrained designs.
Key features of the LT1790BCS6-5 include a low dropout voltage suitable for low-headroom rails, a supply current typically under 60 µA, low output noise, and reverse-battery protection. The 'B' grade's 25 ppm/°C drift makes it well suited to instrumentation that must hold calibration across temperature swings without an external chopper amplifier. Because each part is post-package trimmed, the as-shipped accuracy specification is guaranteed without user adjustment, simplifying factory calibration steps in high-volume builds.
Typical applications include precision ADC and DAC reference rails, industrial process-control signal chains, battery-powered instrumentation, automotive sensor modules, and portable medical devices. Designers also use the LT1790BCS6-5 as a stable bias source for precision current loops and as a low-cost upgrade for legacy 5V reference designs that need tighter initial accuracy and better long-term stability.
A key design consideration is output-capacitor selection. The TSOT-23 part requires careful bypassing close to the output pin to maintain phase margin, and the load current must remain inside the 5 mA envelope to preserve regulation and temperature performance. A short, low-ESR trace from the reference to the load pin reduces dynamic error when the load is an ADC reference input.
This page synthesizes verified distributor pricing, pin-compatible SOT-23 reference alternatives, and application-specific design guidance not present in the standalone Analog Devices datasheet.
Bộ thay thế dễ dàng lắp đặt cho LT1790BCS6-5 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
LT1790ACS6-5
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LT1790CCS6-5
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LT1790BCS6-3.3
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LT1790BCS6-2.5
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LT1790BCS6-4.096
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
ISL21007BFB825Z
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LT1790BCS6-5 Thông số kỹ thuật
| Reference Type | Series, micropower, low dropout |
| Điện áp đầu ra | 5 V (fixed) |
| Initial Accuracy (B grade) | ±0.1% |
| Temperature Coefficient | 25 ppm/°C |
| Output Current | 5 mA |
| Khoảng nhiệt độ hoạt động | 0 °C to +70 °C (commercial, C grade) |
| Hộp | TSOT-23-6 (S6) |
| Số chân | 6 |
| Kiểu lắp đặt | Surface Mount |
| Lead Finish | Lead-free (Pb-free) |
| Cấp MSL | 1 (per JEDEC J-STD-020) |
| Trạng thái RoHS | Compliant |
| Trim Method | Post-package trim, no external adjustment required |
Cấu hình chân LT1790BCS6-5
| Chân 1 | VIN — Input supply voltage |
| Chân 2 | GND — Ground |
| Chân 3 | NC — No connection (per datasheet) |
| Chân 4 | NC — No connection (per datasheet) |
| Chân 5 | VOUT — Regulated 5 V reference output |
| Chân 6 | NC — No connection (per datasheet) |
Ứng dụng tiêu biểu
LT1790BCS6-5 phù hợp cho 6 Áp dụngs: Precision ADC Reference Rail, Industrial Process Control Signal Chain, Portable Battery-Powered Instrumentation, Automotive Sensor Module Reference, Precision DAC and Digital Potentiometer Bias, Medical Monitoring and Diagnostic Devices.
Precision ADC Reference Rail
The LT1790BCS6-5 supplies a stable 5.000 V rail for precision successive-approximation and delta-sigma ADCs that require a low-noise, low-drift reference. With ±0.1% initial accuracy and 25 ppm/°C temperature coefficient, the part's output error is dominated by the ADC's reference-rejection behavior, not the reference itself. Placed between a low-noise LDO (such as an ADP7104) and the ADC's REF pin with a 1 µF X7R bypass capacitor, the LT1790BCS6-5 keeps conversion gain stable across production and field-temperature swings. Unlike buried-Zener references that require 5 mA minimum bias, this part pulls only tens of microamperes, making it ideal for portable 16-18 bit data-acquisition systems. The TSOT-23-6 footprint fits in the same copper keepout area as a typical op-amp, leaving ample room for ground pours and isolation traces around the analog front-end.
Được đề xuất
Industrial Process Control Signal Chain
In 4-20 mA loop-powered transmitters, RTD conditioning boards, and PLC analog input modules, the LT1790BCS6-5 provides the calibration anchor against which pressure, flow, and temperature signals are scaled. The 5 V fixed output matches the common-mode range of most industrial 24 V ADC front-ends, while the 25 ppm/°C drift ensures that a factory-calibrated board stays within its published accuracy spec across the -40 °C to +85 °C industrial ambient. Because each part is post-package trimmed, no production laser trim or EEPROM calibration is needed - a clear BOM cost reduction versus older bandgap-only references. Combined with a TI INA128 instrumentation amplifier (or a discrete INA) and a low-pass RC filter, the LT1790BCS6-5 anchors a sub-0.1% accurate analog front-end that is stable across multi-year deployment.
Được đề xuất
Portable Battery-Powered Instrumentation
Battery-powered multimeters, handheld oscilloscopes, and field data loggers depend on the LT1790BCS6-5's micropower quiescent current and small package to extend runtime and shrink PCB area. Drawing tens of microamperes from a 9 V or 6 V battery, the part keeps working when a switching reference would have already drained the cell. The fixed 5 V output is convenient for biasing op-amps, ADC references, and ratiometric bridge networks where the supply also serves as the excitation source. Reverse-battery protection on the input prevents field-replacement errors from destroying the reference, an important reliability feature in portable test gear that lives in tool bags.
Được đề xuất
Automotive Sensor Module Reference
Although the B-grade LT1790BCS6-5 is specified for 0 °C to +70 °C, the underlying LT1790 family is widely used in cabin and body-electronics modules where the 5 V reference must remain stable across automotive temperature profiles. The fixed 5 V output is convenient for ratiometric pressure, position, and current-sensor signal chains where the reference voltage also serves as the excitation rail. Compared with discrete Zener + op-amp references, the LT1790BCS6-5 shrinks the BOM, drops calibration steps, and provides a known thermal-coefficient budget for sensor error analysis. For under-hood applications requiring -40 °C to +125 °C operation, designers migrate to the I-grade version of the family.
Được đề xuất
Precision DAC and Digital Potentiometer Bias
The LT1790BCS6-5's low noise and tight initial accuracy make it an excellent bias reference for precision DACs, digital potentiometers, and programmable gain amplifiers that need a fixed absolute-voltage anchor. Connecting VOUT to the DAC's VREF pin (or the digital pot's reference inputs) yields a stable full-scale voltage regardless of supply variation, improving linearity and differential non-linearity (DNL). The 5 mA output current capability comfortably supports multiple DAC reference pins in a small analog subsection, and the 6-pin TSOT-23 footprint fits directly under the DAC's exposed thermal pad on the same copper island.
Được đề xuất
Medical Monitoring and Diagnostic Devices
In patient monitors, blood-gas analyzers, and portable diagnostic instruments, the LT1790BCS6-5 provides a stable 5 V reference for the analog front-end that conditions biosensor signals (ECG, SpO2, glucose). The low quiescent current extends battery life in ambulatory monitors, while the ±0.1% initial accuracy preserves the calibrated gain of the front-end over the device's service life. Combined with a low-noise instrumentation amplifier (such as an AD8221) and a 16+ bit sigma-delta ADC, the reference anchors the measurement chain such that small biosignal amplitudes remain resolvable across the device's specified dynamic range. The TSOT-23-6 footprint keeps the analog section compact enough to fit on the smallest wearable form factors.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LT1790BCS6-5 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | LT1790ACS6-5 | LT1790CCS6-5 | LT1790BCS6-3.3 | LT1790BCS6-2.5 | ISL21007BFB825Z |
|---|---|---|---|---|---|---|
| Package | TSOT-23-6 | TSOT-23-6 - same | TSOT-23-6 - same | TSOT-23-6 - same | TSOT-23-6 - same | SOT-23-6 - same footprint |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Renesas (formerly Intersil) |
| Output Voltage | 5.000 V | 5.000 V - same | 5.000 V - same | 3.300 V | 2.500 V | 5.000 V |
| Initial Accuracy | ±0.1% (B grade) | ±0.05% (A grade, tighter) | ±0.2% (C grade, looser) | ±0.1% (B grade, same) | ±0.1% (B grade, same) | ±0.1% |
| Temperature Coefficient | 25 ppm/°C max | 10 ppm/°C max (tighter) | 50 ppm/°C max (looser) | 25 ppm/°C max (same) | 25 ppm/°C max (same) | ~25 ppm/°C max |
| Output Current | 5 mA | 5 mA | 5 mA | 5 mA | 5 mA | 5 mA |
| Operating Temperature Range | 0 °C to +70 °C (commercial) | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +125 °C (wider) |
| RoHS / Lead-Free | Yes / Yes | Yes / Yes | Yes / Yes | Yes / Yes | Yes / Yes | Yes / Yes |
Bảo phân biệt quan trọng
- Lower cost than A grade with same package footprint (vsLT1790ACS6-5)
- Higher accuracy than C grade at modest cost premium (vsLT1790CCS6-5)
- Industrial-grade alternatives available in same family (vsISL21007BFB825Z (Renesas))
Ghi chú thiết kế
Estimated: with VIN = 7 V and 5 mA load on a 5 V reference, the LT1790BCS6-5 dissipates roughly (7 V − 5 V) × 5 mA = 10 mW. The TSOT-23-6 has θJA near 250 °C/W (estimated based on JEDEC EIA/JESD51 standard 4-layer test board for SOT-23-6), so the junction temperature rise is ≈ 2.5 °C above ambient - well within the 0 °C to +70 °C commercial range, but keep VIN-VOUT dropout margin in check to avoid saturating the series pass element. For battery-powered designs, the micropower quiescent current (typically <60 µA) is the dominant battery drain, not the load current.
Place a 0.1 µF to 1 µF low-ESR X7R ceramic bypass capacitor within 2-3 mm of the VOUT pin (pin 5) on the LT1790BCS6-5 to maintain phase margin and prevent oscillation. Use a wide ground pour on pin 2 (GND) and route the load trace as a short, low-impedance Kelvin-style connection from VOUT to the load pin. Avoid placing noisy digital or switching traces directly above or beside the TSOT-23-6 footprint, as the reference output noise can couple into adjacent signals on the top layer.
Do not operate the LT1790BCS6-5 with the output pin unloaded - the post-package trim relies on a defined minimum load. Also avoid reverse polarity on VIN (the part has reverse-battery protection but excessive reverse current can still damage the device). When upgrading a board design from the A grade to the B grade or vice versa, verify that the temperature coefficient and drift budget meet the system's calibration-accuracy requirements, not just the initial-accuracy number. Finally, do not bypass VOUT with a tantalum-only capacitor - low-ESR ceramic is required for stability.
The LT1790BCS6-5's output noise is dominated by the reference's own noise density, which can be coupled into downstream ADC conversion results as a small offset variation. To minimize this, place the reference on the same ground plane as the ADC and use a guard trace around the VOUT node where possible. Adding a small RC low-pass filter (10 Ω + 1 µF) between VOUT and the ADC reference pin further reduces wideband noise at the cost of a small settling-time penalty during ADC acquisition.
Thông tin tuân thủ
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified (commercial grade, 0 °C to +70 °C). Halogen-free and conflict-minerals status not explicitly stated in retrieved web data - left as 'unknown'.
