MIC5318-1.8YMT - 300mA 1.8V ULDO Regulator | Microchip | 6-TMLF
MPN: MIC5318-1.8YMT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.95 | $0.95 |
| 10 | $0.82 | $8.20 |
| 100 | $0.66 | $66.00 |
| 500 | $0.49 | $245.00 |
| 1,000 | $0.39 | $390.00 |
MIC5318-1.8YMT Overview
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is very close to the output voltage. The MIC5318 belongs to the broader category hierarchy: ULDO -> LDO -> linear regulator -> voltage regulator -> power management IC. Compared with a standard NPN LDO, the MIC5318's PMOS pass topology enables an extremely low dropout of typically 90 mV at 300 mA, so a 2.5 V source can still regulate 1.8 V even as the cell discharges.
Key differentiating specifications include 300 mA continuous output current, 90 mV typical dropout at full load, 60 dB PSRR at 1 kHz, 30 uVrms output noise, and 2% initial output voltage accuracy. The device tolerates ceramic output capacitors (uCap), requires no external compensation network, and integrates an active-low enable input for power sequencing in multi-rail designs. Thermal shutdown and current-limit protection are built in.
Architecturally the MIC5318 uses a PMOS pass transistor paired with a precision bandgap reference and a discrete-loop error amplifier. The 6-TMLF exposed-pad package provides a low thermal resistance of approximately 78 C/W, allowing 300 mA delivery without external heatsinking at moderate VIN-VOUT differentials. Quiescent current is typically 90 uA with logic-low EN.
Typical applications include portable and battery-powered devices where board space is critical, image sensors, GPS modules, RF power amplifiers, micro-controller cores, and noise-sensitive analog front ends. The fixed 1.8 V output also suits DDR memory termination rails and low-power MCU I/O supplies.
When designing with the MIC5318-1.8YMT, place a 1 uF X5R/X7R ceramic input capacitor as close as possible to VIN and a 1 uF ceramic output capacitor at VOUT; ESR stability is maintained from near zero to 200 mOhm. The exposed pad must be soldered to a copper pour to meet the published thermal resistance.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the standalone manufacturer datasheet, giving procurement and design engineers a single decision-ready reference.
Drop-in alternatives for MIC5318-1.8YMT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MIC5318-1.8YMT (same form factor and footprint) — differing in Dropout Voltage, Enable Pin, Input Voltage Range, Maximum Output Current, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MIC5318-1.8YMT-TR
✅ Drop-In📋 Reference alternative (not in catalog)
MIC5318-1.85YMT
✅ Drop-In📋 Reference alternative (not in catalog)
MIC5318-2.5YMT
✅ Drop-In📋 Reference alternative (not in catalog)
MIC5370-SGYMT-TR
✅ Drop-In📋 Reference alternative (not in catalog)
MIC5371-SMYMT-TR
✅ Drop-In📋 Reference alternative (not in catalog)
MIC5320-MFYMT-TR
✅ Drop-In📋 Reference alternative (not in catalog)
LP5900TLX-1.8
✅ Drop-In✓ In Stock
$0.23 / Unit
View Datasheet →MIC5318-1.8YMT Maximum Ratings & Electrical Characteristics
| Output Type | Fixed |
| Output Voltage | 1.8 V |
| Output Voltage Accuracy | +/-2% (initial) |
| Maximum Output Current | 300 mA |
| Input Voltage Range | 2.5 V to 6 V |
| Dropout Voltage | 90 mV typical at 300 mA |
| Output Noise | 30 uVrms (10 Hz to 100 kHz) |
| PSRR | 60 dB at 1 kHz |
| Quiescent Current | 90 uA typical |
| Enable Pin | Yes (active-low) |
| Operating Temperature | -40C to +125C |
| Package | 6-TMLF (1.6 mm x 1.6 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Thermal Resistance (theta_JA) | 78 C/W (typical, 4-layer JEDEC board) |
| MSL Level | 1 |
| RoHS Status | Compliant |
MIC5318-1.8YMT Pin Configuration
| Pin 1 | VIN — Input voltage supply; place 1uF ceramic bypass capacitor close to this pin |
| Pin 2 | GND — Ground reference |
| Pin 3 | EN — Enable input (active-low); logic-low enables the regulator, logic-high puts the device in shutdown |
| Pin 4 | NC — Not connected (per datasheet) |
| Pin 5 | VOUT — Regulated 1.8 V output; place 1uF ceramic capacitor close to this pin |
| Pin 6 | EP (GND) — Exposed thermal pad; must be soldered to ground copper pour for thermal dissipation |
Typical Applications
MIC5318-1.8YMT is suitable for 6 applications: Single-Cell Li-Ion Battery Powered Devices, RF Power Amplifier and Front-End Supply, Image Sensor and Camera Module Power, Low-Power MCU Core and I/O Supply, GPS/GNSS Module Power Rail, Industrial Sensor Node and IoT Endpoint.
Single-Cell Li-Ion Battery Powered Devices
The MIC5318-1.8YMT fits portable single-cell Li-Ion designs where a 1.8 V rail is required with minimal quiescent current. With VIN range 2.5 V to 6 V and only 90 mV dropout at 300 mA, the regulator continues to deliver a clean 1.8 V even as the battery discharges from 4.2 V to ~2.7 V, extending usable runtime. Its 90 uA quiescent current preserves standby battery life, and the 1.6x1.6 mm 6-TMLF package fits wearables, fitness bands, and handheld instruments where board area is at a premium.
Recommended
RF Power Amplifier and Front-End Supply
The MIC5318-1.8YMT's 30 uVrms output noise and 60 dB PSRR at 1 kHz make it a strong fit for RF power-amplifier and LNA supply rails where any regulator switching ripple would degrade EVM and phase noise. The PMOS pass element adds no low-frequency noise beyond the 30 uVrms floor, and the fast load-transient response of a ULDO keeps the rail stable during PA burst-current transitions. Use a 1 uF X7R input and output capacitor pair placed within 3 mm of the IC pins.
Recommended
Image Sensor and Camera Module Power
Compact CMOS image sensors and camera modules typically require a low-noise 1.8 V analog rail in addition to a higher digital rail. The MIC5318-1.8YMT delivers up to 300 mA in a 6-TMLF that fits inside camera stick and module enclosures, with 30 uVrms noise that does not couple into the pixel or ADC reference path. The exposed pad provides a 78 C/W thermal path so 300 mA peaks during preview/video modes do not trigger thermal shutdown in ambient temperatures up to 85 C.
Recommended
Low-Power MCU Core and I/O Supply
Many ARM Cortex-M0/M4 microcontrollers run their core or I/O ring at 1.8 V when the system bus is 3.3 V, and the MIC5318-1.8YMT is sized to deliver the 100 mA to 300 mA peaks demanded during active mode. With 90 mV dropout, the regulator stays in regulation even at low battery voltages, and the active-low enable pin allows the MCU to power-gate the rail for deep-sleep modes. Pair the regulator with a 3.3 V upstream buck and use the EN pin as a sequenced wake-up signal.
Recommended
GPS/GNSS Module Power Rail
GPS/GNSS receivers require an ultra-low-noise supply to avoid degrading the carrier-to-noise ratio and time-to-first-fix. The MIC5318-1.8YMT provides a stable 1.8 V rail with 60 dB PSRR at 1 kHz, attenuating any ripple from a shared switching converter upstream. The small 6-TMLF package fits alongside GNSS modules in patch-antenna modules, asset trackers, and fleet management hardware. A 1 uF X7R output capacitor maintains stability during the receiver's acquisition-mode current spikes.
Recommended
Industrial Sensor Node and IoT Endpoint
In industrial 4-20 mA loop-powered or 24 V bus sensor nodes, the MIC5318-1.8YMT can post-regulate from a 3.3 V or 5 V rail down to 1.8 V for an ADC, MCU, or wireless transceiver. Its -40 C to +125 C operating range handles the harsh industrial environment, and the exposed-pad package offers 78 C/W theta_JA for reliable operation inside sealed enclosures. The 2% initial output accuracy is sufficient for most 12-bit ADC reference rails without additional calibration.
Recommended
Recommended Products Summary
Engineering reference data for MIC5318-1.8YMT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MIC5318-1.8YMT-TR | MIC5318-1.85YMT | MIC5318-2.5YMT | MIC5370-SGYMT-TR | MIC5371-SMYMT-TR | MIC5320-MFYMT-TR | LP5900TLX-1.8 |
|---|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Texas Instruments |
| Package | 6-TMLF (1.6x1.6) | 6-TMLF (1.6x1.6) - same | 6-TMLF (1.6x1.6) - same | 6-TMLF (1.6x1.6) - same | 6-TMLF (1.6x1.6) - same | 6-TMLF (1.6x1.6) - same | 6-TMLF (1.6x1.6) - same | DSBGA-6 (0.9x1.6) - similar footprint |
| Output Voltage | 1.8 V | 1.8 V | 1.85 V | 2.5 V | Dual: 1.8 V + 2.8 V | Dual: 1.8 V + 3.3 V | 1.5 V + 2.8 V (dual) | 1.8 V |
| Maximum Output Current | 300 mA | 300 mA | 300 mA | 300 mA | 150 mA per rail | 200 mA per rail | 150 mA per rail | 150 mA |
| Input Voltage Range | 2.5 V to 6 V | 2.5 V to 6 V | 2.5 V to 6 V | 2.5 V to 6 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.3 V to 5.5 V | 2.5 V to 5.5 V |
| Approx. Unit Price (qty 1000) | $0.39 | $0.39 | $0.42 (est.) | $0.42 (est.) | $0.55 (est.) | $0.60 (est.) | $0.50 (est.) | $0.45 (est.) |
Key Differentiators
- Highest output current in the MIC5318 family (vs MIC5320-MFYMT-TR)
- Lower-noise than the TI LP5900TLX-1.8 at comparable output current (vs LP5900TLX-1.8)
- Single-output simplicity in dual-output footprint (vs MIC5371-SMYMT-TR)
Design Notes
Place a 1 uF X5R/X7R ceramic input capacitor within 3 mm of the VIN pin and a 1 uF X5R/X7R ceramic output capacitor within 3 mm of the VOUT pin. The MIC5318-1.8YMT is stable with ceramic output capacitors having ESR from near zero to 200 mOhm. Do not use tantalum or aluminum polymer capacitors - their ESR is too high for this ULDO family.
Estimated: at VIN = 3.6 V, VOUT = 1.8 V, IOUT = 300 mA, power dissipation = (3.6 - 1.8) * 0.3 = 0.54 W. With theta_JA = 78 C/W on a 4-layer JEDEC board, junction temperature rise = 42 C above ambient; at 60 C ambient this stays well below the 150 C thermal-shutdown limit. The exposed pad MUST be soldered to a continuous ground copper pour to achieve the rated theta_JA - a starved pad will degrade thermal performance significantly.
Do not float the EN pin - it MUST be tied to GND (logic-low) to enable the regulator. Floating EN can cause indeterminate startup behavior. Also, avoid routing high-current digital traces directly under the exposed pad without a thermal via array; both inductance and copper-thieving can compromise regulation. When using the MIC5318-1.8YMT in noise-sensitive circuits, add a small ferrite bead on the upstream rail to prevent upstream switching noise from coupling into the ULDO input.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - for automotive applications consider the MIC5318 family variants with explicit automotive grade designations or alternative AEC-Q100 LDOs.
