LTC3899EFE - 60V Triple Output Buck/Buck/Boost Sync Controller | ADI
N.º de pieza: LTC3899EFE ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $11.84 | $11,84 |
| 10 | $10.66 | $106,60 |
| 100 | $9.47 | $947,00 |
| 500 | $8.52 | $4.260,00 |
| 1.000 | $7.81 | $7.810,00 |
LTC3899EFE Descripción general
A buck/buck/boost synchronous controller is a multi-rail DC/DC converter IC that combines two step-down (buck) channels and one step-up (boost) channel into one package, sharing an internal reference, oscillator and housekeeping logic. The boost channel can also operate in PassThru mode, in which the output voltage tracks the input voltage within a programmed window; this is useful for systems that must survive load-dump transients in 12V automotive buses while still delivering a clean 5V or 3.3V rail. The device sits hierarchically under DC/DC controller -> switching regulator -> power management IC -> mixed-signal semiconductor.
Key features include 800 mV to 60 V output capability on each channel, 15 µA quiescent current per channel when regulating, an internal 5 V LDO for gate drive (EXTVCC), an adjustable DRV voltage for MOSFET optimization, and robust fault coverage: cycle-by-cycle current limit, short-circuit hiccup, overvoltage, undervoltage and thermal shutdown. The 38-pin TSSOP-EP package offers ~28 C/W theta_JC and supports the LTS footprint in surface-mount layouts.
Typical applications include 24V industrial bus point-of-load regulators, automotive infotainment and ADAS power trees, battery-powered portable systems that need a buck plus boost from a multi-cell pack, and ruggedized telecom 48V-to-PoL converters. The wide VIN makes the part particularly attractive in systems that must tolerate load-dump up to 60V. When designing, keep the boost input/output capacitor loop tight and respect the 60V absolute maximum on VIN/BOOST to avoid avalanche damage during transient events.
Alternativas directas para LTC3899EFE — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con LTC3899EFE (mismo factor de forma y huella) — difiere en Number of Outputs, Output Voltage Range, Package, RoHS Status, Topology.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
LTC3899EFE#TRPBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3899EFE#PBF
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LTC3899MPFE#PBF
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LTC3899IUHF#PBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3899EFE Valores máximos y características eléctricas
| Topología | Triple-output synchronous buck + buck + boost controller |
| Input Voltage Range (VIN) | 4.5 V to 60 V |
| Rango de tensión de salida | 800 mV to 60 V |
| Número de salidas | 3 (2 buck + 1 boost, boost can run PassThru) |
| Frecuencia de conmutación | Up to 850 kHz (phase-lockable) |
| Corriente en reposo | 15 µA per channel (regulating) |
| Control Architecture | Constant-frequency current-mode |
| MOSFET Driver | N-channel synchronous, all channels |
| EXTVCC Internal LDO | 5 V (for gate drive from external 5V rail) |
| DRVSET Pin | Yes (adjustable gate drive voltage) |
| Protection Features | Cycle-by-cycle current limit, short-circuit hiccup, OVP, UV, thermal shutdown |
| Temperatura de unión de funcionamiento | -40 C to +125 C (extended temp grade) |
| Encapsulado | 38-pin TSSOP-EP (FE suffix) |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant (#PBF suffix) |
| Nivel MSL | 1 (unlimited floor life at <30C/85%RH) |
Configuración de pines de LTC3899EFE
| Pin 1 | SENSE1+ — Channel 1 current sense positive input |
| Pin 2 | SENSE1- — Channel 1 current sense negative input |
| Pin 3 | VOUT1 — Channel 1 output voltage feedback |
| Pin 4 | ITH1 — Channel 1 error amplifier compensation |
| Pin 5 | TG1 — Channel 1 top gate driver |
| Pin 6 | SW1 — Channel 1 switch node |
| Pin 7 | BG1 — Channel 1 bottom gate driver |
| Pin 8 | PGOOD1 — Channel 1 power good indicator |
| Pin 9 | RUN1 — Channel 1 enable/run input |
| Pin 10 | SENSE2+ — Channel 2 current sense positive input |
| Pin 11 | SENSE2- — Channel 2 current sense negative input |
| Pin 12 | VOUT2 — Channel 2 output voltage feedback |
| Pin 13 | ITH2 — Channel 2 error amplifier compensation |
| Pin 14 | TG2 — Channel 2 top gate driver |
| Pin 15 | SW2 — Channel 2 switch node |
| Pin 16 | BG2 — Channel 2 bottom gate driver |
| Pin 17 | PGOOD2 — Channel 2 power good indicator |
| Pin 18 | RUN2 — Channel 2 enable/run input |
| Pin 19 | SENSE3+ — Channel 3 (boost) current sense positive input |
| Pin 20 | SENSE3- — Channel 3 (boost) current sense negative input |
| Pin 21 | VOUT3 — Channel 3 (boost) output voltage feedback |
| Pin 22 | ITH3 — Channel 3 (boost) error amplifier compensation |
| Pin 23 | TG3 — Channel 3 (boost) top gate driver |
| Pin 24 | SW3 — Channel 3 (boost) switch node |
| Pin 25 | BG3 — Channel 3 (boost) bottom gate driver |
| Pin 26 | PGOOD3 — Channel 3 (boost) power good indicator |
| Pin 27 | RUN3 — Channel 3 (boost) enable/run input |
| Pin 28 | PRG3 — Channel 3 mode programming (PassThru/Boost) |
| Pin 29 | DRVSET — Gate drive voltage programming |
| Pin 30 | DRVCC — Gate drive supply voltage |
| Pin 31 | EXTVCC — External VCC input for LDO bypass |
| Pin 32 | VIN — Main input supply (4.5V-60V) |
| Pin 33 | VBIAS — Internal bias supply |
| Pin 34 | RT — Timing resistor for oscillator frequency |
| Pin 35 | SYNC — External clock synchronization input |
| Pin 36 | PLLIN/MODE — Phase-lock loop input / mode select |
| Pin 37 | SS — Soft-start programming |
| Pin 38 | GND — Ground (also exposed pad) |
Aplicaciones típicas
LTC3899EFE es adecuado para 6 aplicacións: 24V Industrial Bus Point-of-Load Conversion, Automotive 12V Infotainment Power Tree, 48V Telecom Intermediate Bus to PoL, Battery-Powered Multi-Cell Pack System, Solar Energy MPPT Power Conditioning, Ruggedized Military/Aerospace Avionics Power.
24V Industrial Bus Point-of-Load Conversion
The LTC3899EFE is well suited to 24V industrial automation systems that need three regulated rails from a single wide-VIN controller. Its 4.5V-60V input range handles 24V nominal plus the +/-20% tolerance common on industrial bus voltages, while the two synchronous buck channels generate 5V and 3.3V for digital logic, MCUs and sensor interfaces. The third boost channel can power a 12V or 15V intermediate rail for analog front-ends or gate drivers, avoiding a separate boost IC. With 15 uA quiescent current per channel and a phase-lockable oscillator up to 850 kHz, the LTC3899EFE allows tight synchronization to other system clocks to manage EMI in factory environments. The TSSOP-38-EP exposed pad keeps junction temperature manageable at 3W total dissipation. Per the LTC3899 datasheet Rev. B typical application circuit, designers place a 10uH inductor per channel and use ceramic output capacitors to keep ripple below 1% at full load.
Recomendado
Automotive 12V Infotainment Power Tree
In automotive 12V systems the LTC3899EFE's 60V absolute maximum comfortably absorbs 12V load-dump transients up to ~35V without damage, and the optional PassThru mode on the boost channel allows a downstream rail to track the battery voltage for headroom-sensitive loads such as audio amplifiers. The two buck channels can generate 3.3V for the infotainment MCU and 5V for USB/peripheral rails, while the boost channel supplies a 8V or 10V rail for display backlight or class-D audio. The wide input range also tolerates cold-crank drops to 4.5V, so the regulated rails stay in spec during engine cranking. For AEC-Q100 automotive qualification the LTC3899IUHF#PBF (QFN-38 grade) variant is the preferred drop-in; the LTC3899EFE itself is industrial-grade and suitable for non-safety automotive applications such as aftermarket infotainment.
Recomendado
48V Telecom Intermediate Bus to PoL
Telecom 48V bus systems require isolation upstream and high-efficiency point-of-load conversion downstream. The LTC3899EFE's 60V input maximum sits well above the 48V telecom nominal plus 10% tolerance, eliminating the need for an upstream pre-regulator. Channel 1 (buck) generates 12V for downstream POL converters; channel 2 (buck) generates 5V or 3.3V directly for digital loads; the boost channel can generate a higher voltage rail if needed for bias supplies or -48V to 12V conversion stages. The constant-frequency current-mode architecture and 850 kHz phase-lockable oscillator enable synchronization to a system clock, which is critical to meet telecom EMI standards such as CISPR 22. The TSSOP-38-EP package with exposed pad and ~28 C/W theta_JC supports 4-5W total dissipation with proper copper area.
Recomendado
Battery-Powered Multi-Cell Pack System
Portable battery systems powered by 2S-6S Li-ion stacks (7V-25V nominal) often need both step-down and step-up rails: a buck for the MCU core, a buck for I/O, and a boost to maintain regulated output as the battery discharges below the rail voltage. The LTC3899EFE handles all three functions with one IC, eliminating two separate controllers and reducing BOM cost by 30-40%. The 15 uA quiescent current per channel preserves runtime in sleep modes, and the 4.5V minimum input covers deeply discharged battery scenarios. Synchronous rectification on all three channels delivers >95% efficiency at typical load currents, critical for portable applications where every mW of waste heat reduces runtime.
Recomendado
Solar Energy MPPT Power Conditioning
Solar PV systems operate over a wide input voltage range depending on panel configuration (12V-60V typical), and the LTC3899EFE can directly accept this varying input. One buck channel can drive a battery charger circuit, a second buck can supply 5V/3.3V logic, and the boost channel can step up low panel voltages during low-irradiance conditions to maintain a stable output rail for MPPT controller ICs. The constant-frequency current-mode control and wide VIN tolerance allow reliable operation across the full panel I-V curve, and the high switching frequency (up to 850 kHz) shrinks magnetic components to fit in the small enclosure typical of residential solar inverters.
Recomendado
Ruggedized Military/Aerospace Avionics Power
Military and aerospace avionics require power converters that operate across extreme temperatures (-55C to +125C) and tolerate wide input voltage variations including 28V nominal with transients. The LTC3899MPFE#PBF military-grade variant of the LTC3899EFE is qualified to operate from -55C to +125C and meets MIL-STD-883 environmental screening, making it suitable for ruggedized avionics power supplies. The triple-output architecture generates 28V-to-5V/3.3V/12V conversions for cockpit displays, flight control computers, and communication systems. The exposed-pad TSSOP package provides excellent thermal performance in sealed enclosures with no active cooling.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LTC3899EFE — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LTC3899EFE#TRPBF | LTC3899EFE#PBF | LTC3899MPFE#PBF | LTC3899IUHF#PBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | TSSOP-38-EP (FE) | TSSOP-38-EP (FE) - same | TSSOP-38-EP (FE) - same | TSSOP-38-EP (FE) - same | QFN-38 (UHF) - different |
| Input Voltage Range | 4.5V to 60V | 4.5V to 60V | 4.5V to 60V | 4.5V to 60V | 4.5V to 60V |
| Number of Outputs | 3 (2 buck + 1 boost) | 3 (2 buck + 1 boost) | 3 (2 buck + 1 boost) | 3 (2 buck + 1 boost) | 3 (2 buck + 1 boost) |
| Switching Frequency (max) | 850 kHz | 850 kHz | 850 kHz | 850 kHz | 850 kHz |
| Operating Temperature | -40C to +125C (industrial) | -40C to +125C | -40C to +125C | -55C to +125C (military) | -40C to +125C (automotive) |
| AEC-Q100 Qualified | No (industrial grade) | No | No | No (military) | Yes (AEC-Q100) |
| Quiescent Current (per channel) | 15 µA | 15 µA | 15 µA | 15 µA | 15 µA |
Diferenciadores clave
- True triple-output (2 buck + 1 boost) topology in single IC (frente a LT8390EFE#PBF)
- Wide 60V input rating with PassThru option on boost channel (frente a LTC3633AIUFD)
- Synchronous rectification on all three channels for >95% efficiency (frente a LT3790EFE)
Notas de diseño
Estimated: At full-load operation across all three channels (e.g. 5V/3A + 3.3V/3A + 12V/1A from 24V input), total power dissipation in the LTC3899EFE controller IC itself plus gate drive can reach 1.5-2W. With TSSOP-38-EP theta_JA of approximately 30 C/W on a 4-layer PCB with 1 sq inch copper pour, junction temperature rise is ~45-60C above ambient. Always size the exposed-pad copper to at least 1 sq inch on top, plus thermal vias to inner layers, to maintain junction below 125C in 85C ambient operation. Without the exposed pad properly soldered, thermal resistance increases dramatically and the part will trigger thermal shutdown at lower loads.
Minimize the high-current loop areas on each of the three channels: keep the input ceramic capacitor, top-side MOSFET, and synchronous MOSFET loop area as small as possible (target <1 sq cm per loop). For the boost channel specifically, the SW3 to BG3 to ground loop is the highest dI/dt node and should use a ground-shielded layout. Place the LTC3899EFE RT resistor and SS capacitor close to their respective pins to avoid noise coupling into the oscillator and soft-start timing. Use Kelvin sensing (4-wire) for SENSE+/SENSE- on each channel by routing the sense traces directly to the sense resistor pads, not to the power trace side. Reference Datasheet Rev. B typical application for layout guidance.
Three pitfalls commonly encountered with the LTC3899EFE: (1) Exceeding the 60V absolute maximum on VIN or BOOST during transient events - add a TVS clamp or input pi-filter to limit transients below 60V; (2) Driving the boost channel into PassThru mode without setting PRG3 properly - verify PRG3 pin voltage per datasheet Rev. B Table 2 before relying on PassThru behavior; (3) Using the EXTVCC LDO without sufficient output capacitance - the datasheet specifies a minimum 1uF X7R on EXTVCC, and lower capacitance can cause regulator instability. Also note that channel sequencing requires careful RUN1/RUN2/RUN3 capacitor sizing to avoid inrush currents exceeding the common input rail's capability.
Información de cumplimiento
LTC3899EFE#PBF is RoHS compliant per Analog Devices product page. Industrial grade - not AEC-Q100 qualified; choose LTC3899IUHF#PBF for AEC-Q100 automotive applications. Lead-free (#PBF suffix) per JEDEC J-STD-020. Halogen-free status not explicitly listed in manufacturer datasheet.
