LTC3788IGN-1 - 2-Phase Dual Sync Boost Controller | Analog Devices
N.º de pieza: LTC3788IGN-1 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $7.42 | $7,42 |
| 10 | $6.68 | $66,80 |
| 100 | $5.95 | $595,00 |
| 500 | $5.25 | $2.625,00 |
| 1.000 | $4.7 | $4.700,00 |
| 3.000 | $4.1 | $12.300,00 |
LTC3788IGN-1 Descripción general
A boost (step-up) DC-DC controller is a switching regulator topology whose output voltage is always greater than its input voltage. It uses an inductor, a power switch, and a rectifier to first store energy in the inductor then release it into the output capacitor at a higher voltage. A controller (as opposed to a converter) only provides the gate-drive and feedback signals, while the actual power devices (MOSFETs) are external to the IC. The "2-phase" architecture means two parallel power stages are operated 180 degrees out of phase, which halves the input ripple current, doubles the effective ripple frequency, and reduces input capacitor stress - making it ideal for high-current applications. The "synchronous" part means the rectifier diode is replaced by a MOSFET, lowering conduction losses especially at high current and large duty cycles.
Key features of the LTC3788-1 include a precision 1.2V reference, dual power good output indicators, programmable current limit, and adjustable operating frequency that can be synchronized to an external clock. The 28-SSOP package offers a compact footprint suitable for industrial power supplies, automotive systems, and battery-powered equipment where high step-up ratios are needed. The wide 4.5V to 38V input range encompasses most battery chemistries including single-cell Li-ion, multi-cell lead-acid, and 24V industrial rails.
The architecture uses a peak current-mode control loop, which simplifies loop compensation, provides inherent cycle-by-cycle current limiting, and eases paralleling of multiple phases. Phase shedding at light load and adaptive dead-time control optimize efficiency across the load range. The LTC3788-1 also features soft-start programmability and output voltage tracking for multi-rail sequencing.
Typical applications include high-power LED drivers, automotive start-stop systems, 24V to 48V industrial bus boost, TFT LCD bias supplies, and battery-powered portable equipment where step-up conversion is required. The dual-phase architecture especially shines in applications drawing more than 10A continuous, where single-phase solutions would require excessively large inductors.
When designing with the LTC3788-1, attention to PCB layout is critical because switching nodes can exceed 60V with high di/dt. Keep the high-current loop area minimal, use a ground plane, and place input capacitors close to both MOSFET half-bridges. Use the exposed pad of the SSOP-28 GN package for proper thermal dissipation; failure to do so may cause thermal shutdown at high output power.
This page synthesizes distributor pricing, datasheet specifications, pinout, drop-in alternatives, and practical design notes that go beyond the manufacturer datasheet alone.
Alternativas directas para LTC3788IGN-1 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
LTC3788EGN-1#PBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3788IGN-1#TRPBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3788EGN#PBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3788EGN
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC3788IGN-1 Valores máximos y características eléctricas
| Topología | Boost (Step-Up) |
| Número de salidas | 2 (2-phase) |
| Rectificador síncrono | Yes (drives N-channel MOSFETs) |
| Rango de tensión de entrada | 4.5 V to 38 V |
| Rango de tensión de salida | Up to 60 V |
| Tensión de referencia | 1.2 V (precision) |
| Control Method | Peak Current-Mode |
| Frecuencia de conmutación | Programmable, synchronizable to external clock |
| Power Good Outputs | 2 (dual PG indicators) |
| Output Current Capability | Externally limited by MOSFET selection (controller only) |
| Limitación de corriente | Programmable via sense resistor |
| Arranque suave | Programmable |
| Rango de temperatura de funcionamiento | -40 C to +125 C (industrial grade) |
| Package Type | 28-SSOP (GN) with exposed thermal pad |
| Package Width | 3.90 mm (0.154 in) |
| Tipo de montaje | Surface Mount |
| Lead Free / RoHS | Lead-free (PBF suffix), RoHS compliant |
| Manufacturer | Analog Devices (formerly Linear Technology) |
Configuración de pines de LTC3788IGN-1
| Pin 1 | PGND1 — Power Ground for phase 1 |
| Pin 2 | SW1 — Phase 1 switch node |
| Pin 3 | BOOST1 — Phase 1 bootstrap capacitor |
| Pin 4 | TG1 — Phase 1 top gate drive |
| Pin 5 | BG1 — Phase 1 bottom gate drive |
| Pin 6 | SENSE1+ — Phase 1 current sense positive |
| Pin 7 | SENSE1- — Phase 1 current sense negative |
| Pin 8 | VCC — Internal 5V regulator bypass |
| Pin 9 | VIN — Main input supply |
| Pin 10 | RUN/SS1 — Phase 1 run / soft-start |
| Pin 11 | RT — Timing resistor for oscillator |
| Pin 12 | SYNC — External clock synchronization |
| Pin 13 | PGND2 — Power Ground for phase 2 |
| Pin 14 | SW2 — Phase 2 switch node |
| Pin 15 | BOOST2 — Phase 2 bootstrap capacitor |
| Pin 16 | TG2 — Phase 2 top gate drive |
| Pin 17 | BG2 — Phase 2 bottom gate drive |
| Pin 18 | SENSE2+ — Phase 2 current sense positive |
| Pin 19 | SENSE2- — Phase 2 current sense negative |
| Pin 20 | VOUT — Output voltage sense |
| Pin 21 | FB — Feedback (sets VOUT via divider) |
| Pin 22 | COMP — Compensation network |
| Pin 23 | PG1 — Phase 1 power good output |
| Pin 24 | PG2 — Phase 2 power good output |
| Pin 25 | ITH — Current threshold / error amp output |
| Pin 26 | REF — 1.2V reference bypass |
| Pin 27 | INTVCC — Internal VCC bypass |
| Pin 28 | RUN/SS2 — Phase 2 run / soft-start |
Aplicaciones típicas
LTC3788IGN-1 es adecuado para 6 aplicacións: High-Power LED Driver, Automotive Start-Stop Boost, 24V to 48V Industrial Bus Boost, TFT LCD Bias Supply, Battery-Powered Portable Boost, Power over Ethernet (PoE) Boost.
High-Power LED Driver
The LTC3788IGN-1's 4.5V-38V input and up to 60V output directly addresses high-brightness LED strings requiring 20V to 48V compliance voltage at multi-amp drive current. The 2-phase architecture reduces input ripple current by half compared to single-phase designs, allowing smaller input bulk capacitors and reducing stress on upstream automotive or industrial 12V/24V rails. Compared to a discrete single-phase boost, the LTC3788-1 cuts inductor size by ~50% through interleaving. Typical companion parts are high-current LED arrays with thermal foldback; pair with a current-sense amplifier such as LT6105 or with MOSFET drivers from the LT1910 family to drive the synchronous rectifier stages. The 1.2V precision reference maintains output voltage accuracy within 1% across -40C to +125C for consistent LED luminance.
Recomendado
Automotive Start-Stop Boost
The LTC3788IGN-1 is ideal for automotive 12V start-stop boost applications where the battery voltage can dip below 6V during engine cranking and must be boosted back to a stable 12V rail for infotainment and ECU power. Its 4.5V to 38V VIN range handles cranking transients, and the up-to-60V VOUT capability covers 24V or 48V mild-hybrid architectures. The 2-phase design keeps input ripple current low, protecting the vehicle battery from high-frequency stress. Synchronous rectification recovers efficiency that would otherwise be lost in the boost rectifier, especially critical at the high duty cycles typical of low-VIN start-stop operation. Pair with automotive-grade MOSFETs and add reverse-battery protection with a P-FET for full automotive compliance.
Recomendado
24V to 48V Industrial Bus Boost
The LTC3788IGN-1 targets industrial 24V-48V bus boost conversion for factory automation, PLCs, and motor drives requiring higher compliance voltage from a 24V nominal rail. With VIN 4.5V-38V covering 24V industrial supplies with margin and VOUT up to 60V covering 48V targets, the LTC3788-1 is well-matched. The 2-phase 180-degree interleaving cuts input current ripple amplitude by half and doubles the effective switching frequency, simplifying input EMI filtering. Peak current-mode control provides cycle-by-cycle protection and simple Type-II compensation. Industrial -40C to +125C operating range matches factory floor requirements. For multi-rail systems, pair with isolated DC-DC modules downstream for safety isolation, or with sequencing supervisors for orderly power-up.
TFT LCD Bias Supply
The LTC3788IGN-1 generates the AVDD, VGH, and VGL bias rails for TFT LCD panels used in industrial displays and automotive clusters. Its up-to-60V output capability covers VGH (gate-high, typically 20V-35V) and VGL (gate-low, typically -5V to -15V when used with a charge pump), while its 1.2V precision reference ensures stable bias for pixel switching accuracy. The 2-phase architecture is essential here because LCD panels draw multi-amp currents with tight ripple requirements - input ripple must be low to avoid display artifacts. Synchronous rectification also reduces heat in space-constrained backlight driver boards. Compare to a boost + LDO cascade, the LTC3788-1's PG outputs enable direct sequencing with the source driver rails.
Battery-Powered Portable Boost
The LTC3788IGN-1 fits battery-powered applications including 1- to 4-cell Li-ion packs, multi-cell NiMH, and 12V lead-acid systems where step-up conversion to 24V or 48V is needed for downstream Class-D audio amplifiers, motor drivers, or USB-PD sources. Its 4.5V minimum VIN handles deeply discharged battery conditions, and programmable soft-start prevents inrush current that could trip battery protection. The 2-phase operation halves input RMS ripple, extending battery life by reducing AC losses in the source impedance. Light-load efficiency can be optimized by phase shedding in single-phase mode at low loads. For USB-PD source applications, the LTC3788-1's VOUT range covers 5V, 9V, 15V, 20V, and 48V PD profiles up to 60V.
Recomendado
Power over Ethernet (PoE) Boost
The LTC3788IGN-1 boosts PoE input voltages (typically 36V-57V from the PD interface) to higher voltages needed for specialized industrial loads or for 100V+ bias rails in high-voltage analog front-ends. Its 60V maximum VOUT covers most PoE applications including PoE+ (Type 2, 25.5W) and PoE++ (Type 3, 60W) source voltages with margin. The wide VIN range accommodates PoE's variable input voltage during load transients, and the 2-phase design handles the multi-amp currents typical of full-power PoE applications. Synchronous rectification maximizes efficiency at the high duty cycles used for small step-up ratios. Add hot-swap controllers on the input for PoE inrush limiting and IEEE 802.3 compliance.
Resumen de productos recomendados
Datos de referencia de ingeniería para LTC3788IGN-1 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LTC3788EGN-1#PBF | LTC3788IGN-1#TRPBF | LTC3788EGN#PBF | LTC3788EGN |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-SSOP (GN) | 28-SSOP (GN) - same | 28-SSOP (GN) - same | 28-SSOP (GN) - same | 28-SSOP (GN) - same |
| Topology | 2-phase sync boost controller | 2-phase sync boost controller (same) | 2-phase sync boost controller (same) | 2-phase sync boost controller (non -1 variant) | 2-phase sync boost controller (non -1 variant) |
| Input Voltage Range | 4.5 V to 38 V | 4.5 V to 38 V | 4.5 V to 38 V | 4.5 V to 38 V | 4.5 V to 38 V |
| Output Voltage Range | Up to 60 V | Up to 60 V | Up to 60 V | Up to 60 V | Up to 60 V |
| Oscillator Variant | -1 (2-phase optimized) | -1 (same) | -1 (same) | non -1 (different oscillator) | non -1 (different oscillator) |
| Operating Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C |
| Lead Free (PBF) | Yes (#PBF suffix) | Yes (#PBF suffix) | Yes (#TRPBF suffix) | Yes (#PBF suffix) | Non-PBF (legacy) |
Diferenciadores clave
- True 2-phase 180-degree interleaved operation (frente a LTC3788EGN#PBF (non -1 variant))
- Wide 4.5V-38V VIN supports battery and industrial rails (frente a Single-phase boost controllers like LT3753IFE)
- Up to 60V VOUT covers PoE, LED, and TFT bias rails (frente a Lower-voltage boost controllers)
Notas de diseño
Switching node layout is critical for the LTC3788IGN-1 because the SW1 and SW2 pins can swing above 60V with high di/dt. Keep the high-current loop (input cap -> top MOSFET -> SW -> bottom MOSFET -> PGND) area minimal and use a ground plane. Place the input ceramic capacitors (X7R, 1uF to 4.7uF) as close to each phase's MOSFET half-bridge as physically possible. According to the LTC3788-1 datasheet, exceeding 60V on SW or BOOST pins can permanently damage the IC. Use wide PCB traces for power paths and minimize via count on switching current loops.
The 28-SSOP GN package has an exposed thermal pad that MUST be soldered to the PCB ground plane for proper heat dissipation. The package thermal resistance is approximately theta_JA = 30 C/W with a properly laid out 4-layer PCB with 1oz copper. While the LTC3788IGN-1 controller itself dissipates little power (most is in the external MOSFETs), inadequate exposed pad soldering can cause thermal shutdown under high-frequency or high-voltage operation. Use thermal vias under the exposed pad to the inner-layer ground plane, with at least 9 vias in a 3x3 array for optimal thermal conductivity.
Common pitfalls when designing with the LTC3788IGN-1: (1) do not omit the bootstrap capacitor (typically 100nF to 470nF X7R) on each BOOST pin - without it, the top gate drive cannot turn on the high-side MOSFET; (2) ensure the current sense resistor value matches the controller's SENSE+ / SENSE- common-mode range, especially important at low VIN where sense voltage approaches ground; (3) the SYNC input requires a logic-level signal, not a level-shifted one - use a clock buffer if the source is a high-voltage gate driver output; (4) program soft-start with a sufficiently long time constant (typically 1ms to 100ms) to prevent input inrush that can trip upstream fuses or battery protection.
The LTC3788IGN-1's 2-phase 180-degree interleaving is itself an EMI mitigation technique because it places input ripple at twice the per-phase switching frequency, moving it above the AM broadcast band and into less-sensitive frequency regions. For additional EMI margin, use a pi-filter (LC) on the input, with the inductor sized for approximately 10x attenuation at the fundamental. Spread-spectrum frequency modulation (SSFM) is NOT supported by this part, but EMI can be further reduced by using controlled slew-rate MOSFETs. Per the LTC3788-1 datasheet, switching frequency synchronization to an external clock can be used to place switching harmonics away from sensitive frequencies.
Información de cumplimiento
Lead-free PBF suffix denotes RoHS-compliant lead finish. No AEC-Q100 automotive qualification - contact Analog Devices for automotive-grade equivalents. Halogen free status not explicitly listed in provided web data.
