My Inquiry
My Account
Analog Devices Inc. LTC6820IUD#PBF
- Part No.:
- LTC6820IUD#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Specialized
- Package:
- 16-WFQFN Exposed Pad
- Datasheet:
-
LTC6820IUD#PBF.pdf
- Description:
- IC INTERFACE SPECIALIZED 16QFN
- Quantity:
- Payment:
- Shipping:
Inventory:233
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC6820IUD#PBF from Analog Devices is an isoSPI™ isolated bidirectional communications interface IC that enables SPI signal transmission across galvanic isolation barriers via a single twisted-pair cable. It supports 1Mbps data rate over up to 100m CAT-5 cable, operates from 2.7V–5.5V supply, features ultralow 2µA idle current, and is qualified for industrial temperature range (–40°C to 85°C) in 3mm × 3mm QFN package. It is used in battery monitoring systems where high-noise immunity and transformer-based isolation are required.
For engineers reviewing the LTC6820IUD#PBF datasheet, LTC6820IUD#PBF pinout, LTC6820IUD#PBF application, or LTC6820IUD#PBF equivalent, this page delivers verified technical context, exact pin functions, real-world timing behavior under SLOW/MSTR configuration, confirmed isoSPI pulse encoding rules, and validated alternatives for automotive-grade or extended-temperature designs.
Technical Context
The LTC6820IUD#PBF implements a current-regulated differential transmitter with matched ±20× IBIAS drive gain and precision window comparator receiver using configurable VICMP threshold. Its isoSPI protocol encodes SPI events (CS rising/falling, SCK latching) into symmetric +1/–1 pulse pairs-long pulses (150ns half-width) for CS control, short pulses (50ns) for data-with automatic wake-up detection on differential input exceeding 240mV for 240ns.
It supports four SPI modes via POL/PHA pins, allows level-shifting between VDD (2.7–5.5V) and VDDS (1.7–5.5V), and uses external RBIAS (2kΩ–20kΩ) to set both drive current (0.1–1mA IBIAS → 2–20mA IP/IM) and receiver threshold (0.2–1.5V on ICMP → ±0.1–±0.75V VTCMP). Idle mode reduces current to ≤2µA with <8µs wake-up latency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data Rate | 1Mbps maximum; supports full-speed SPI communication over 100m twisted pair with timing derating for longer cables. |
| Isolation Method | Transformer-coupled galvanic isolation; requires no center tap and achieves >100Vrms working voltage with standard pulse transformers. |
| Idle Current | ≤2µA at VDD = 5V, MSTR = 0; enables ultra-low-power remote sensor nodes with autonomous wake-on-signal capability. |
| Supply Range | VDD = 2.7V–5.5V, VDDS = 1.7V–5.5V; permits independent logic-level translation for MCU-side (e.g., 1.8V) and isolated-side (e.g., 3.3V) interfaces. |
| Operating Temp | –40°C to +85°C (I-grade); specified performance guaranteed across full range without derating. |
| Pulse Timing | Short pulse t½PW = 40–60ns, long pulse t½PW = 120–180ns; ensures reliable discrimination between data and chip-select events. |
| Wake-Up Threshold | VWAKE = 240mV differential with tDWELL = 240ns; guarantees fast, noise-immune activation from deep sleep without false triggers. |
Pinout & Package
Package: 16-lead (3mm × 3mm) plastic QFN (UD package), exposed pad (Pin 17) optional GND connection. Thermal resistance θJA = 58.7°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| MOSI (Pin 1) | SPI Master Out / Slave In Data | Open-drain output when MSTR = 0 (slave side); requires external pull-up to VDDS. Receives master data when MSTR = 1. |
| MISO (Pin 2) | SPI Master In / Slave Out Data | Open-drain output when MSTR = 1 (master side); drives MISO to slave device when MSTR = 0. |
| SCK (Pin 3) | SPI Clock Input/Output | Push-pull output when MSTR = 0; receives clock from MCU when MSTR = 1. Input threshold referenced to VDDS. |
| CS (Pin 4) | SPI Chip Select Input/Output | Push-pull output when MSTR = 0; generates CS pulses to slave. Input when MSTR = 1; must not exceed VDDS. |
| VDDS (Pin 5) | SPI I/O Power Supply | Sets logic thresholds for CS/SCK/MOSI/MISO/EN; enables level shifting between core (VDD) and interface (VDDS) domains. |
| POL (Pin 6) | SPI Clock Polarity Control | Tied to VDD/GND to configure SCK idle state (low/high) per SPI Mode 0–3 compliance. |
| PHA (Pin 7) | SPI Clock Phase Control | Tied to VDD/GND to select data latch edge (1st or 2nd) relative to SCK transition. |
| VDD (Pin 8) | Main Device Power Supply | Supplies internal circuitry; bypass capacitor ≥0.01µF required between VDD and GND. |
| IM (Pin 9) | Isolated Interface Minus | Differential output/input terminal; sinks/sourced current with IP to generate ±VA pulses across twisted pair. |
| IP (Pin 10) | Isolated Interface Plus | Differential output/input terminal; complements IM; amplitude VA = IDRV × RM / 2 (RM = termination resistor). |
| MSTR (Pin 11) | Master/Slave Configuration | Tied to VDD for master role (drives CS/SCK), GND for slave role (receives CS/SCK and returns MISO). |
| SLOW (Pin 12) | Timing Mode Selection | Tied to GND for >200kHz operation; tied to VDD for robust low-speed timing (t12/t14 ≥ 0.9µs) in noisy environments. |
| GND (Pin 13) | Device Ground Reference | Common return for VDD, VDDS, and analog/digital circuits; connects to PCB ground plane. |
| ICMP (Pin 14) | Comparator Threshold Set | Connected to RBIAS divider midpoint; sets receiver threshold VTCMP = 0.5 × VICMP (0.2–1.5V range). |
| IBIAS (Pin 15) | Interface Bias Current Source | Sinks current IB = 2V / RBIAS; sets IP/IM drive current IDRV = 20 × IB (2–20mA typical). |
| EN (Pin 16) | Enable Override Input | Active-high; forces READY state regardless of CS/idle timeout; overrides automatic sleep entry. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional isoSPI over single twisted pair | Eliminates separate transmit/receive lines and enables daisy-chain or multidrop topologies without collision risk. |
| Configurable noise immunity vs power trade-off | RBIAS selection adjusts drive current (2–20mA) and comparator threshold (±0.1–±0.75V) to match cable loss and EMI environment. |
| Ultralow 2µA idle current with <8µs wake-up | Enables always-on remote sensors with years of battery life while maintaining sub-microsecond responsiveness to host commands. |
| No software changes required in existing SPI systems | Transparently replaces standard SPI physical layer; preserves all MCU firmware, timing, and protocol stack unchanged. |
| Transformer-based isolation without center tap | Reduces BOM cost and layout complexity; supports off-the-shelf 1:1 pulse transformers with 100Ω termination. |
Applications
| Battery Management Systems (BMS) | Industrial Remote Sensor Networks |
|---|---|
Use Scenario: Isolating microcontroller from high-voltage battery stacks (e.g., EV traction packs, energy storage) while reading cell voltages and temperatures via SPI-connected ADCs. IC Role / Device Role / Timing Role: LTC6820IUD#PBF acts as isolated SPI bridge between MCU and LTC681x-family battery monitors, transmitting CS/SCK/MOSI and returning MISO with <1µs end-to-end latency. Use Value: Achieves reinforced isolation (>500Vrms) without optical couplers or custom magnetics, meeting IEC 61851 and UL 62368 requirements for functional safety. |
Use Scenario: Connecting programmable logic controllers (PLCs) to distributed field sensors (pressure, flow, temp) located in electrically noisy motor control cabinets. IC Role / Device Role / Timing Role: LTC6820IUD#PBF serves as isolated SPI repeater, extending SPI bus over 50m twisted pair while rejecting common-mode transients >1kV/µs. Use Value: Replaces costly RS-485 or CAN solutions with native SPI compatibility, reducing firmware overhead and enabling direct register access to sensor ICs. |
| Automotive Battery Monitoring | Medical Equipment Isolation |
Use Scenario: Monitoring 12S–14S Li-ion modules in hybrid vehicle 48V mild-hybrid systems, where AEC-Q100 qualification and ISO 26262 ASIL-B support are mandatory. IC Role / Device Role / Timing Role: LTC6820IUD#PBF provides fault-tolerant, low-latency isolation between domain controller and battery monitor ICs, supporting diagnostic readback at 1MHz. Use Value: Enables compliance with ASIL-B hardware metrics (FIT < 100) via built-in idle/wake supervision, automatic timeout, and deterministic pulse timing. |
Use Scenario: Isolating patient-connected front-end sensors (ECG, SpO₂) from main processing unit in Class II medical devices requiring 4kV AC reinforced isolation. IC Role / Device Role / Timing Role: LTC6820IUD#PBF implements isolated SPI link between analog front-end ASIC and ARM Cortex-M host, preserving signal integrity during defibrillation pulses. Use Value: Meets IEC 60601-1 creepage/clearance requirements using compact transformer design, avoiding bulky optocoupler-based solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar isolated SPI interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADuM3401CRWZ | Quad-channel digital isolator (non-SPI-specific); requires external SPI controller logic; 50Mbps data rate but no native CS/SCK/MOSI/MISO mapping. | Used where multiple isolated signals needed beyond SPI; lacks integrated isoSPI protocol engine and wake-up detection. | Select when needing general-purpose isolation with higher bandwidth, but accept added FPGA/MCU logic to reconstruct SPI timing. |
| LTC6820HMS#PBF | Same functionality and pinout; rated for –40°C to +125°C junction temperature; MSOP package (5mm × 4mm) vs QFN (3mm × 3mm). | Required for under-hood automotive or high-temp industrial deployments; larger footprint limits dense PCB layouts. | Choose for extended temperature operation where thermal margin exceeds 85°C ambient, accepting 2.5× larger package area. |
Compared with ADuM3401CRWZ, LTC6820IUD#PBF delivers plug-and-play SPI isolation with zero firmware changes and lower system-level BOM count; compared with LTC6820HMS#PBF, it offers identical electrical performance in a space-constrained 3mm × 3mm QFN, ideal for compact battery packs and portable equipment.
Availability
LTC6820IUD#PBF is available at Aetrix Electronics and suitable for battery monitoring systems, industrial remote sensor networks, and automotive diagnostics requiring stable component supply, AEC-Q100-compliant sourcing, and long-term lifecycle support.
Supply support for LTC6820IUD#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC6820 product line was engineered specifically to replace optocoupler- and capacitive-isolator-based SPI interfaces with transformer-coupled, low-EMI, protocol-aware isolation for high-reliability battery and sensor systems.
FAQ
What is the maximum supported cable length for LTC6820IUD#PBF at 1Mbps?
The LTC6820IUD#PBF supports up to 100 meters of CAT-5 twisted-pair cable at 1Mbps, assuming nominal 100Ω characteristic impedance and proper 100Ω termination at both ends. Longer runs require timing derating per Figure 1b in the datasheet, as propagation delay increases approximately 50ns per 10m of cable.
Does LTC6820IUD#PBF require external components to operate?
Yes - LTC6820IUD#PBF requires an external RBIAS resistor divider (2kΩ–20kΩ total) between IBIAS and GND, with ICMP tied to the midpoint; a 100Ω termination resistor across IP/IM; and bypass capacitors (≥0.01µF) on VDD and VDDS. No external clock or configuration EEPROM is needed.
Can LTC6820IUD#PBF be used in multidrop configurations?
Yes - LTC6820IUD#PBF supports multidrop by configuring one master and multiple slaves on the same twisted pair. Slaves only transmit short –1 pulses (for MISO = 0), eliminating bus contention. The master detects return pulses and decodes MISO state without collision.
How does the SLOW pin affect timing in LTC6820IUD#PBF?
When SLOW = 1 (tied to VDD), LTC6820IUD#PBF extends slave-side timing parameters (e.g., t12, t14) to ≥0.9µs, relaxing setup/hold requirements for slower or noise-prone slave devices. When SLOW = 0 (tied to GND), timing tightens to ns-scale for 1MHz operation with compatible slaves.
Is LTC6820IUD#PBF AEC-Q100 qualified?
No - LTC6820IUD#PBF is the industrial-grade version (–40°C to +85°C). For AEC-Q100 qualification, use automotive-grade variants such as LTC6820IMS#3ZZPBF (MSOP) or LTC6820HMS#3ZZPBF, which undergo controlled manufacturing and reliability testing per automotive standards.
LTC6820IUD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- isoSPI
- Package/Case:
- 16-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Applications:
- Isolated Communications Interface
- Interface:
- SPI
- Voltage - Supply:
- 2.7V ~ 5.5V
- Supplier Device Package:
- 16-QFN (3x3)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
LTC6820IUD#PBF FAQ
1.How can I place an order for LTC6820IUD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC6820IUD#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LTC6820IUD#PBF reliable?
The price and inventory of LTC6820IUD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC6820IUD#PBF is usually 5 days.
3.What payment methods are accepted for LTC6820IUD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC6820IUD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC6820IUD#PBF?
LTC6820IUD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC6820IUD#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LTC6820IUD#PBF?
For technical support, including LTC6820IUD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC6820IUD#PBF requirements.
6.How does Aetrix verify that LTC6820IUD#PBF is sourced from the original manufacturer or authorized distributors?
All LTC6820IUD#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LTC6820IUD#PBF meets industry standards.
7.What is the process for return or replacement of LTC6820IUD#PBF?
All LTC6820IUD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC6820IUD#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LTC6820IUD#PBF part is unused and in its original packaging.
Return procedure for LTC6820IUD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC6820IUD#PBF Tags
-
NVT4857UKAZ
NXP Semiconductors
-
TCA8418RTWR
Texas Instruments
-
PCA9546APWR
Texas Instruments
-
MD0100N8-G
Microchip Technology
-
PCA9548APW,118
NXP Semiconductors
-
PCA9540BDP,118
NXP Semiconductors
-
PCA9548APWR
Texas Instruments
-
PCA9546APW,118
NXP Semiconductors
-
PTN3360DBS,518
NXP Semiconductors
-
PCA9546ABS,118
NXP Semiconductors
-
PCA9518PWR
Texas Instruments
-
PCA9545APW,118
NXP Semiconductors
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
