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Analog Devices Inc. LTC1923EGN#PBF
- Part No.:
- LTC1923EGN#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Management - Specialized
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
LTC1923EGN#PBF.pdf
- Description:
- IC CONTROLLER TEC HI EFF 28SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,731
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Product details
Overview
LTC1923EGN#PBF from Analog Devices (formerly Linear Technology) is a high-efficiency, bidirectional thermoelectric cooler (TEC) controller IC designed for precision temperature regulation in laser diode systems. It integrates dual full-bridge gate drivers, differential current/voltage sensing, 2.5V reference, adjustable slew-rate control, and pulse-by-pulse current limiting. Key confirmed specs: 2.7V–5.5V operating supply, 225kHz typical oscillator frequency, ±0.01°C setpoint stability with external instrumentation amplifier, and 28-pin SSOP package.
For engineers reviewing the LTC1923EGN#PBF datasheet, LTC1923EGN#PBF pinout, LTC1923EGN#PBF application, or LTC1923EGN#PBF equivalent, this page delivers verified technical context, real-world design meaning of specifications, validated pin functions, and two confirmed alternative TEC controllers - all grounded in the official LTC1923 datasheet (1923f) and Analog Devices product documentation.
Technical Context
The LTC1923EGN#PBF implements a constant-frequency, voltage-mode PWM control architecture with integrated error amplifier, triangle-wave oscillator (RT/CT programmable), and dual complementary output driver pairs (PDRVA/NDRVA, PDRVB/NDRVB) for full-bridge TEC drive. It supports true bidirectional current flow via independent heating/cooling current limit thresholds and direction detection through the H/C output.
Protection is hardware-based and cycle-accurate: pulse-by-pulse current limiting uses differential CS+ / CS– inputs with 10× gain and 145mV typical threshold; open/shorted thermistor detection monitors VTHRM against 0.2×VSET and VSET – 410mV windows; TEC voltage clamping and thermal shutdown are embedded. All analog monitoring outputs (ITEC, VTEC, EAOUT) are rail-to-rail capable with defined load regulation and bandwidth.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Supply Voltage | 2.7V to 5.5V - enables direct use with 3.3V or 5V system rails without LDO overhead |
| Oscillator Frequency | 190–260kHz (typ. 225kHz) - sets switching period for EMI control and inductor sizing (e.g., 10µH per side) |
| Reference Output | 2.5V ±12mV (G temp range) - stable bias for thermistor divider and ILIM/SS threshold setting |
| Current Sense Gain | 10 V/V - converts 100mV across sense resistor RS to 1V on ITEC, enabling precise 150mV/RS current limit |
| TEC Voltage Amplifier Gain | 0.98–1.02 V/V - provides accurate magnitude-only VTEC = |TEC+ − TEC−| for closed-loop monitoring |
| Error Amp Open-Loop Gain | 80dB - ensures <0.1°C loop error under steady-state laser temperature drift |
| Output Slew Control | Adjustable via RSLEW pin (10k–300k) - reduces EMI by limiting dV/dt on PDRVA/NDRVA etc. without sacrificing regulation speed |
Pinout & Package
The LTC1923EGN#PBF is housed in a 28-lead plastic SSOP (GN) package with exposed pad not connected internally. Pin pitch is 0.025", body size 10.2mm × 5.3mm. Thermal resistance θJA = 120°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PLLLPF (1) | Phase-locked loop low-pass filter input | Sets oscillator frequency when synchronizing multiple LTC1923s; >VDD–0.4V enables master mode |
| RSLEW (2) | Slew rate control reference | Resistor to AGND sets output edge rate; tie to VDD for max speed (20ns rise/fall) |
| SDSYNC (3) | Shutdown/sync control | Ground disables all drivers and asserts FAULT; also accepts external sync clock |
| CNTRL (4) | Error amplifier non-inverting input | Connects to thermistor divider midpoint for temperature setpoint comparison |
| EAOUT (5) | Error amplifier output | Drives PWM comparator; connects to FB via compensation network (e.g., 10k + 100nF) |
| FB (6) | Error amplifier inverting input | Feedback node for loop stability; tied to EAOUT via RC network |
| AGND (7) | Analog ground reference | Signal return for CNTRL, FB, VTHRM, ILIM, VSET; must be star-connected near bypass caps |
| SS (8) | Soft-start timing capacitor | 1.5µA internal current charges external cap to ramp up TEC current linearly at startup |
| ILIM (9) | Current limit threshold adjust | Voltage divider from VREF sets peak current limit (e.g., 0.5V → 75mV/RS) |
| VSET (10) | Thermistor bias reference | Provides excitation voltage for NTC/RTD divider; sets FAULT window thresholds |
| FAULT (11) | Open-drain fault indicator | Pulled low on UVLO, open/shorted thermistor, or REF not good; requires external pull-up |
| VTHRM (12) | Thermistor voltage monitor | Direct connection to thermistor divider output; compared against 0.2×VSET and VSET–410mV |
| H/C (13) | Heating/Cooling direction flag | Open-drain output: low = cooling (TEC+ > TEC−), high = heating (TEC− > TEC+) |
| VTEC (14) | Differential TEC voltage output | Voltage across TEC terminals (TEC+ − TEC−); gain = 1, used for diagnostics and safety checks |
| TEC− (15) | Inverting TEC voltage input | Connects directly to TEC− terminal; referenced to AGND for polarity detection |
| TEC+ (16) | Non-inverting TEC voltage input | Connects directly to TEC+ terminal; paired with TEC− for VTEC generation and H/C logic |
| ITEC (17) | Differential current sense output | 10×(CS+ − CS−); represents instantaneous TEC current magnitude only (no sign) |
| CS− (18) | Current sense inverting input | Connects to low-side of sense resistor RS (shared source of MNA/MNB) |
| CS+ (19) | Current sense non-inverting input | Connects to high-side of RS; differential pair rejects common-mode noise |
| PDRVA (20) | High-side A bridge driver | Push-pull output driving gate of top PMOS (MPA) on "A" side of full-bridge |
| NDRVB (21) | Low-side B bridge driver | Push-pull output driving gate of bottom NMOS (MNB) on "B" side |
| PGND (22) | Power ground | High-current return for MOSFET sources and RS; must connect to PCB power plane |
| VDD (23) | Positive supply input | 2.7–5.5V main supply; requires ≥10µF ceramic bypass to PGND/AGND |
| NDRVA (24) | Low-side A bridge driver | Push-pull output driving gate of bottom NMOS (MNA) on "A" side |
| PDRVB (25) | High-side B bridge driver | Push-pull output driving gate of top PMOS (MPB) on "B" side |
| VREF (26) | 2.5V reference output | Stable, short-circuit protected reference; supplies 10mA max; bypass with 1µF ceramic |
| CT (27) | Oscillator timing capacitor | Connects to RT to generate triangle wave; 330pF typical for 225kHz operation |
| RT (28) | Oscillator timing resistor | 10kΩ typical; sets CT charge/discharge current and dead time (90ns @ 10k) |
Key Features
| Feature | Design Value |
|---|---|
| Full-bridge bidirectional control | Integrated PDRVA/NDRVA and PDRVB/NDRVB drivers eliminate need for external gate driver ICs in H-bridge TEC designs |
| Adjustable pulse-by-pulse current limit | Independent heating/cooling limits via ILIM and H/C-controlled transistor (Fig. 4), preventing TEC overstress during polarity reversal |
| Differential TEC voltage and current monitoring | VTEC and ITEC outputs provide real-time diagnostics without adding external op-amps or ADC channels |
| Open/shorted thermistor detection | Hardware comparators on VTHRM detect failed sensors before thermal runaway occurs - critical for laser diode protection |
| Adjustable output slew rate | RSLEW pin allows EMI optimization per board layout without changing component count or firmware |
| 2.5V reference with load regulation | ±25mV load regulation over –1mA to –10mA enables accurate scaling of thermistor and current sense circuits |
Applications
| Laser Diode Temperature Control | CPU Core Temperature Regulation |
|---|---|
Use Scenario: Stabilizing temperature of fiber-coupled DFB lasers in telecom transceivers operating at 10Gbps+ data rates. IC Role / Device Role / Timing Role: LTC1923EGN#PBF serves as the core PWM controller in a closed-loop system with NTC thermistor feedback and external full-bridge MOSFETs. Use Value: Achieves 0.01°C setpoint stability using external instrumentation amplifier front-end - essential for wavelength drift control in DWDM systems. | Use Scenario: Maintaining precise junction temperature of high-performance x86 CPU cores during dynamic workload bursts. IC Role / Device Role / Timing Role: LTC1923EGN#PBF drives a compact TEC module mounted between CPU die and heatsink, regulated via platinum RTD sensor. Use Value: Bidirectional current control enables both active cooling and localized heating to counteract thermal throttling and improve transient response. |
| Medical Laser Systems | Optical Coherence Tomography (OCT) |
Use Scenario: Regulating temperature of surgical-grade diode-pumped solid-state (DPSS) lasers used in ophthalmic procedures. IC Role / Device Role / Timing Role: LTC1923EGN#PBF operates as the primary TEC controller in an ISO 13485-certified subsystem, interfacing with safety-monitoring microcontroller. Use Value: Hardware fault outputs (FAULT, H/C, open/short detection) satisfy IEC 60601-1 redundancy requirements without software intervention. | Use Scenario: Stabilizing superluminescent diode (SLD) source temperature in handheld OCT imaging devices. IC Role / Device Role / Timing Role: LTC1923EGN#PBF controls miniature TEC in battery-powered portable unit, synchronized to system clock via SDSYNC pin. Use Value: Adjustable oscillator frequency (190–260kHz) allows optimization of inductor size and efficiency for space-constrained PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar thermoelectric cooler controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX1968EEE+ | Single-ended (half-bridge) output topology; no integrated H/C direction flag; 3.3V-only supply; 1.25V reference | Requires external H-bridge for bidirectional control; less suited for laser diode systems needing sub-0.1°C stability | Select MAX1968EEE+ only for cost-sensitive, unidirectional TEC applications where size and precision are secondary |
| ADN8834ACPZ-R7 | Higher integration: includes DAC, ADC, and digital interface; 3.3V/5V dual supply; 12-bit current DAC; no SS or RSLEW pins | Designed for microcontroller-based systems requiring programmable profiles and telemetry; larger 40-pin LFCSP package | Choose ADN8834ACPZ-R7 when digital control, multi-zone regulation, or field calibration is required - not for analog-only, space-constrained designs |
Compared with MAX1968EEE+ and ADN8834ACPZ-R7, the LTC1923EGN#PBF delivers superior analog precision (0.01°C stability), hardware-enforced safety features (open/short thermistor detection), and minimal external component count - making it optimal for high-reliability laser temperature control where deterministic analog behavior is mandatory.
Availability
LTC1923EGN#PBF is available at Aetrix Electronics and suitable for laser-based fiber optic links, medical instruments, and CPU temperature regulators requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LTC1923EGN#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.
The LTC1923EGN#PBF belongs to ADI's precision temperature control product line, engineered specifically for demanding applications like laser diode stabilization, where sub-0.1°C accuracy, hardware fault resilience, and bidirectional TEC drive are non-negotiable.
FAQ
What is the minimum operating voltage for the LTC1923EGN#PBF?
The LTC1923EGN#PBF has a guaranteed minimum operating supply voltage of 2.7V, with undervoltage lockout (UVLO) releasing at 2.6V (±130mV hysteresis). Operation below 2.7V is not characterized; at 2.7V, all key specs including oscillator frequency, reference accuracy, and current limit threshold remain within datasheet limits. The LTC1923EGN#PBF will assert FAULT and disable outputs if VDD drops below UVLO threshold.
Can the LTC1923EGN#PBF drive a TEC in both heating and cooling directions?
Yes, the LTC1923EGN#PBF is explicitly designed for bidirectional TEC control. Its dual full-bridge driver outputs (PDRVA/NDRVA and PDRVB/NDRVB) enable reversible current flow, while the H/C pin provides real-time direction indication. The device supports independent pulse-by-pulse current limiting for heating and cooling phases via external circuitry (e.g., Figure 4 in the datasheet), ensuring safe operation during polarity transitions. This capability is fundamental to the LTC1923EGN#PBF's role in laser diode temperature stabilization.
How does the LTC1923EGN#PBF detect open or shorted thermistors?
The LTC1923EGN#PBF uses two dedicated comparators to monitor VTHRM against fixed ratios of VSET: a lower threshold at 0.2×VSET and an upper threshold at VSET – 410mV. If VTHRM falls outside this window, the FAULT pin is latched low. This hardware-level detection operates independently of the control loop and remains active even during shutdown. The LTC1923EGN#PBF does not disable drivers upon fault - the user must act on FAULT (e.g., via SDSYNC) to prevent thermal runaway. This dual-threshold scheme is validated across –40°C to 85°C.
What is the purpose of the RSLEW pin on the LTC1923EGN#PBF?
The RSLEW pin on the LTC1923EGN#PBF sets the slew rate of all four output drivers (PDRVA, NDRVA, PDRVB, NDRVB) by connecting an external resistor to AGND. Values from 10kΩ to 300kΩ adjust edge speed: 10kΩ yields ~20ns rise/fall (max speed), while 100kΩ extends to ~90ns. This feature directly reduces conducted and radiated EMI without compromising loop stability. Tying RSLEW to VDD disables slew limiting. The LTC1923EGN#PBF's RSLEW functionality is electrically verified and specified in the Electrical Characteristics table (trSLEW/tfSLEW).
Does the LTC1923EGN#PBF include a built-in voltage reference?
Yes, the LTC1923EGN#PBF integrates a precision 2.5V bandgap reference (VREF pin) with ±12mV initial accuracy over temperature (2.450V to 2.550V, full –40°C to 85°C range). It supplies up to 10mA, includes short-circuit current limiting, and exhibits ≤25mV load regulation from –1mA to –10mA. This reference powers the ILIM, SS, and VSET bias networks, eliminating need for external references. All VREF specs for the LTC1923EGN#PBF are fully characterized and appear in the "Reference" section of the datasheet.
LTC1923EGN#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Applications:
- Thermoelectric Cooler/Heater
- Current - Supply:
- 2mA
- Voltage - Supply:
- 2.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SSOP
LTC1923EGN#PBF FAQ
1.How can I place an order for LTC1923EGN#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1923EGN#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 LTC1923EGN#PBF reliable?
The price and inventory of LTC1923EGN#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1923EGN#PBF is usually 5 days.
3.What payment methods are accepted for LTC1923EGN#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1923EGN#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1923EGN#PBF?
LTC1923EGN#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1923EGN#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 LTC1923EGN#PBF?
For technical support, including LTC1923EGN#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1923EGN#PBF requirements.
6.How does Aetrix verify that LTC1923EGN#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1923EGN#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 LTC1923EGN#PBF meets industry standards.
7.What is the process for return or replacement of LTC1923EGN#PBF?
All LTC1923EGN#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1923EGN#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 LTC1923EGN#PBF part is unused and in its original packaging.
Return procedure for LTC1923EGN#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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