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NXP Semiconductors MC34845EPR2
- Part No.:
- MC34845EPR2
- Manufacturer:
- NXP Semiconductors
- Category:
- LED Drivers
- Package:
- 24-UFQFN Exposed Pad
- Datasheet:
-
MC34845EPR2.pdf
- Description:
- IC LED DRVR RGLTR PWM 2.3A 24QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,027
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Product details
Overview
MC34845EPR2 from NXP Semiconductors is a six-channel LED backlight driver with integrated 2.0 A boost FET, designed for edge-lit LCD displays from 10" to 17". It operates from 5.0 V to 21 V input, delivers up to 60 V boost output, supports 3.0–30 mA per channel with ±2% current matching, and features PWM dimming, dynamic headroom control, and comprehensive fault protection including LED open/short, overtemperature, overcurrent, and overvoltage.
For engineers reviewing the MC34845EPR2 datasheet, MC34845EPR2 pinout, MC34845EPR2 application, or MC34845EPR2 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated package and pin functions, confirmed alternative parts with functional distinctions, and supply-chain support for notebook, portable display, and industrial HMI designs.
Technical Context
The MC34845EPR2 implements a current-mode boost converter with Dynamic Headroom Control (DHC) that automatically adjusts VOUT to match LED string voltage requirements-only active for LED pulse widths >400 ns. Its internal 2.0 A SMARTMOS FET, fixed 300 kHz switching frequency (per EP suffix), and external Type II compensation on COMP enable stable high-efficiency operation across varying LED loads.
It integrates six matched current sinks (CH1–CH6), each programmable via ISET resistor (RSET = 153 / ILED), with channel-to-channel tolerance ≤±2% at 10–30 mA. Fault detection includes OVP (internally fixed 60 V typical, externally adjustable down to 15 V), SFDV (7.0 V typical short-detect threshold), OFDV (0.55 V open-detect threshold), and overtemperature shutdown at 150 °C with 25 °C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5.0 V to 21 V - supports direct 12 V rail or 2–3-cell Li-ion battery input without pre-regulation |
| Boost Output Voltage | Up to 60 V - sufficient for driving up to 16-series LEDs at ~3.5 V each under worst-case forward-voltage spread |
| Integrated Boost FET | 2.0 A minimum - handles peak inductor current in 300 kHz boost topology with margin for thermal derating |
| LED Current Range | 3.0 mA to 30 mA per channel - set by single ISET resistor; 0.1% tolerance recommended for ±2% matching |
| Channel Matching | ±2% max (10–30 mA) - ensures uniform luminance across multi-string edge-lit panels without per-channel calibration |
| OVP Protection | Internally fixed 60 V typical + externally programmable 15–60 V - dual-layer safeguard against boost runaway during LED open faults |
| Thermal Resistance | Junction-to-case 3.1 °C/W - requires exposed pad (EP) soldered to PCB copper for reliable 1.8 W dissipation at 85 °C ambient |
Pinout & Package
MC34845EPR2 is housed in a 24-pin QFN-EP (exposed pad) package (drawing 98ASA00602D), 4 mm × 4 mm × 0.85 mm, with thermal pad grounded for heat dissipation. Pin 1 is VIN; pins 2/5 are PGNDB/PGNDA (separate power grounds for boost FET); EP is GND and thermal enhancement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Main supply input | Powers internal LDOs and boost regulator; UVLO triggers at 4.0–4.4 V rising edge |
| PGNDB / PGNDA (Pins 2, 5) | Boost FET power ground | Separate low-impedance return paths for high di/dt boost switching; must be star-connected to EP |
| SWA / SWB (Pins 4, 3) | Boost switch nodes | Connect to external inductor and Schottky diode; layout critical for EMI and efficiency |
| EN (Pin 6) | Enable control | Active-high logic input; internal pull-down; asserts shutdown mode when low |
| CH1–CH6 (Pins 7–12) | LED current sink outputs | Each drives one LED string cathode; 0.75 V min compliance voltage at 30 mA |
| ISET (Pin 15) | Current reference input | Resistor-to-GND sets LED current via internal 2.043 V reference; RSET = 153 / ILED |
| PWM (Pin 16) | Dimming control | Direct PWM input (DC–100 kHz); modulates LED current duty cycle without affecting boost regulation |
| FAIL (Pin 14) | Open-drain fault indicator | Low-impedance when healthy; high-Z on any fault (OCP, OTP, LED open/short, OVP) |
| OVP (Pin 22) | External overvoltage setting | Accepts resistor divider from VOUT to set OVP threshold between 15 V and 60 V |
| COMP (Pin 17) | Boost compensation node | Connects external Type II network (e.g., 2 kΩ + 33 nF + 220 pF) to stabilize current-mode loop |
Key Features
| Feature | Design Value |
|---|---|
| Dynamic Headroom Control (DHC) | Automatically minimizes VOUT to just above required LED string voltage-reducing power loss and heat in boost stage |
| Six-channel current matching | ≤±2% tolerance across CH1–CH6 at 10–30 mA-enables consistent brightness without per-string trimming |
| Single-wire WAKE control | Enables low-power standby using only PWM signal (with EN grounded)-eliminates need for separate enable line |
| Integrated fault protection suite | Detects and responds to LED open/short, boost overcurrent (>2.1 A), overtemperature (150 °C), and overvoltage (60 V internal) |
| SMARTMOS process technology | Enables monolithic integration of power FET, analog control, and protection circuits in single 24-QFN die |
Applications
| PC Notebook Backlighting | Industrial HMI Displays |
|---|---|
Use Scenario: Driving 6-string edge-lit LED array behind 13.3" or 15.6" TFT-LCD panel powered from 12 V system rail. IC Role / Device Role / Timing Role: Six-channel constant-current sink with integrated boost converter and DHC-based adaptive output voltage control. Use Value: Eliminates discrete boost controller + 6x current drivers; achieves <±2% luminance uniformity across full brightness range using single ISET resistor. |
Use Scenario: Backlighting ruggedized 10.1" medical display operating continuously in 40–85 °C ambient with safety-critical fault reporting. IC Role / Device Role / Timing Role: LED driver with fail-safe OVP, OTP, and open/short detection feeding FAIL pin to system microcontroller. Use Value: Internal 60 V OVP and 150 °C shutdown prevent catastrophic failure; FAIL pin enables immediate UI alert or graceful backlight fade-out on fault. |
| Portable DVD Player Display | GPS Navigation Screen |
Use Scenario: Powering 4-string LED backlight from 7.4 V (2S Li-ion) in space-constrained portable device with battery life optimization. IC Role / Device Role / Timing Role: High-efficiency boost LED driver with 300 kHz switching and PWM dimming interface compatible with baseband processor GPIO. Use Value: 90% peak boost efficiency extends runtime; 3.0–30 mA programmability allows dimming down to minimal current without color shift. |
Use Scenario: Driving 6-string backlight for 7" automotive-grade GPS screen requiring robust operation under wide input voltage (9–16 V) and thermal cycling. IC Role / Device Role / Timing Role: Automotive-qualified LED driver with UVLO hysteresis (0.25 V), -40 to 85 °C operation, and ESD protection (±2 kV HBM). Use Value: Stable current regulation across input and temperature range ensures consistent display brightness during engine cranking or hot parking lot conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED backlight driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3409QMH/NOPB | Single-channel buck-boost LED controller; external MOSFET required; no integrated current sinks or DHC | Requires 6x external controllers + FETs + current sense resistors; higher BOM cost and board area | Choose when flexible topology (buck, boost, SEPIC) or higher than 30 mA/channel is needed |
| TPS61165DRVR | Single-channel boost LED driver; 1.2 A switch; no multi-string current matching or FAIL pin | Lacks channel-to-channel matching and integrated fault reporting-requires external monitoring circuitry | Choose for cost-sensitive single-string applications where uniformity and diagnostics are secondary |
Compared with LM3409QMH/NOPB and TPS61165DRVR, MC34845EPR2 delivers six matched channels, integrated power FET, adaptive DHC, and unified fault signaling in one 4×4 mm QFN-reducing component count by >50% and eliminating inter-channel calibration in mid-size display backlight designs.
Availability
MC34845EPR2 is available at Aetrix Electronics and suitable for PC notebook backlighting, industrial HMI displays, portable DVD player screens, GPS navigation units, and healthcare device interfaces requiring stable component supply, long-term lifecycle support, and automotive-grade reliability.
Supply support for MC34845EPR2 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
NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and consumer applications, with deep expertise in power management and analog mixed-signal ICs.
The MC34845EPR2 belongs to NXP's SMARTMOS LED backlight driver family, engineered specifically for energy-efficient, compact, and fault-resilient edge-lit LCD backlight systems in portable and industrial displays.
FAQ
What is the switching frequency of the MC34845EPR2?
The MC34845EPR2 operates at a fixed 300 kHz boost switching frequency, as indicated by the "D" variant designation in the MC34845 series and confirmed in Table 1 of the datasheet. This frequency balances efficiency, EMI, and external component size-supporting use of standard 22–33 μH inductors and ceramic output capacitors. The MC34845EPR2 does not support frequency adjustment; variants with 600 kHz exist but carry different part numbers (e.g., MC34845CEP).
How is LED current programmed on the MC34845EPR2?
LED current on the MC34845EPR2 is set by connecting a precision resistor (0.1% tolerance recommended) between the ISET pin (Pin 15) and GND. The relationship is RSET = 153 / ILED, where ILED is the desired current per channel in mA. For example, a 5.1 kΩ resistor yields ~30 mA (153 / 30 = 5.1 kΩ). The internal ISET reference voltage is 2.043 V typical, enabling accurate, temperature-stable current setting across all six channels.
Does the MC34845EPR2 support PWM dimming, and how is it implemented?
Yes, the MC34845EPR2 supports direct PWM dimming via the PWM pin (Pin 16), accepting signals from DC to 100 kHz. Unlike analog dimming, this method modulates the LED current sink duty cycle while maintaining constant peak current-preserving color consistency and enabling high-contrast dimming down to 0.1% duty cycle. The IC does not require external PWM-to-analog conversion; the PWM signal directly gates the current sinks with minimal propagation delay (<0.2 μs in operational mode).
What fault protections are built into the MC34845EPR2?
The MC34845EPR2 integrates five core fault protections: (1) LED open detection (OFDV = 0.55 V), (2) LED short detection (SFDV = 7.0 V typical), (3) boost overcurrent (IBOOST_LIMIT = 2.1 A typical), (4) overtemperature shutdown (150 °C with 25 °C hysteresis), and (5) overvoltage protection (internally fixed 60 V typical + externally adjustable 15–60 V). All faults assert the open-drain FAIL pin to high-impedance, allowing system-level fault logging or recovery sequencing.
What is the purpose of the WAKE pin on the MC34845EPR2?
The WAKE pin (Pin 18) enables single-wire low-power standby control: when WAKE and PWM are tied together and EN is held low, the MC34845EPR2 enters shutdown mode if PWM remains low for >27 ms (tSHUTDOWN). This eliminates the need for a dedicated enable signal in space-constrained designs. Upon PWM high transition, the device wakes within soft-start time (~3 ms), resuming LED drive without full power-on reset-ideal for portable devices requiring rapid brightness transitions and ultra-low quiescent current (<10 μA in shutdown).
MC34845EPR2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 24-UFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 5V
- Voltage - Supply (Max):
- 21V
- Voltage - Output:
- 8V ~ 60V
- Current - Output / Channel:
- 2.3A (Switch)
- Frequency:
- 600kHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-QFN-EP (4x4)
MC34845EPR2 FAQ
1.How can I place an order for MC34845EPR2 through Aetrix?
Please submit a Request for Quotation (RFQ) for MC34845EPR2 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 MC34845EPR2 reliable?
The price and inventory of MC34845EPR2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC34845EPR2 is usually 5 days.
3.What payment methods are accepted for MC34845EPR2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC34845EPR2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC34845EPR2?
MC34845EPR2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC34845EPR2 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 MC34845EPR2?
For technical support, including MC34845EPR2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC34845EPR2 requirements.
6.How does Aetrix verify that MC34845EPR2 is sourced from the original manufacturer or authorized distributors?
All MC34845EPR2 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 MC34845EPR2 meets industry standards.
7.What is the process for return or replacement of MC34845EPR2?
All MC34845EPR2 units undergo pre-shipment inspection (PSI). If there is an issue with MC34845EPR2, 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 MC34845EPR2 part is unused and in its original packaging.
Return procedure for MC34845EPR2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC34845EPR2 Tags
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HV9910CLG-G
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