Chip Resistors-Surface Mount

Part Number	Description / PDF	Quantity
WR12W2R43FTL Walsin Technology	RES 2.43 OHM 1% 1/4W 1206	0
WR12X2200FTL Walsin Technology	RES 220 OHM 1% 1/4W 1206	10000
WR12W3R65FTL Walsin Technology	RES 3.65 OHM 1% 1/4W 1206	0
WR12X1690FTL Walsin Technology	RES 169 OHM 1% 1/4W 1206	0
WR12X1182FTL Walsin Technology	RES 11.8K OHM 1% 1/4W 1206	0
WR08W4324FTL Walsin Technology	RES 4.32M OHM 1% 1/8W 0805	0
WR12W2R94FTL Walsin Technology	RES 2.94 OHM 1% 1/4W 1206	0
WR08W9R76FTL Walsin Technology	RES 9.76 OHM 1% 1/8W 0805	0
WR02W2R26FAL Walsin Technology	RES 2.26 OHM 1% 1/20W 0201	0
WR12X5491FTL Walsin Technology	RES 5.49K OHM 1% 1/4W 1206	0
WR06X6803FTL Walsin Technology	RES 680K OHM 1% 1/10W 0603	4900
WR02X333 JAL Walsin Technology	RES 33K OHM 5% 1/20W 0201	29000
WR08W4R12FTL Walsin Technology	RES 4.12 OHM 1% 1/8W 0805	0
WR12W6R98FTL Walsin Technology	RES 6.98 OHM 1% 1/4W 1206	0
WR08W1R91FTL Walsin Technology	RES 1.91 OHM 1% 1/8W 0805	0
WR12X1821FTL Walsin Technology	RES 1.82K OHM 1% 1/4W 1206	0
WR12X1870FTL Walsin Technology	RES 187 OHM 1% 1/4W 1206	0
WR08X2200FTL Walsin Technology	RES 220 OHM 1% 1/8W 0805	0
WR08X335 JTL Walsin Technology	RES 3.3M OHM 5% 1/8W 0805	10000
WR12X4642FTL Walsin Technology	RES 46.4K OHM 1% 1/4W 1206	0

Chip Resistors-Surface Mount

1. Overview

Surface Mount Chip Resistors (SMD Resistors) are passive electronic components designed to limit current flow and divide voltages in printed circuit boards (PCBs). As key elements in Surface Mount Technology (SMT), they enable high-density PCB layouts and automated manufacturing. Their miniaturized footprint and reliability make them essential for modern electronics, including smartphones, automotive systems, and industrial equipment.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Thick Film Resistors	Cost-effective, standard tolerance ( 1%-5%), power ratings up to 1W	Consumer electronics, power supplies
Thin Film Resistors	High precision ( 0.01%), low noise, stable temperature coefficients	Medical devices, precision instrumentation
Power Resistors	High power dissipation (up to 3W), robust thermal management	Motor drives, EV battery management systems
Network Resistors	Multiple resistors in single package, matched temperature coefficients	Digital circuits, memory modules
Wirewound Resistors	High inductance, precise low-resistance values	Audio amplifiers, industrial control systems

3. Structure and Composition

Typical SMD resistors consist of: - Ceramic substrate (Alumina, 96% Al₂O₃) - Resistive layer (Ruthenium oxide for thick film, Nichrome for thin film) - Termination electrodes (Ni/Sn or Ag/Pd metallization) - Protective coating (Epoxy or glass encapsulation) Standard packages follow EIA dimensions (e.g., 0402, 0603, 0805).

4. Key Technical Specifications

Parameter	Description	Importance
Resistance Range	1 to 10M (film), 0.1 to 100k (power)	Determines current control capability
Tolerance	0.01% (precision) to 5% (general)	Impacts circuit accuracy
Power Rating	0.05W to 3W @ 70 C	Defines thermal dissipation limits
TCR	5ppm/ C (thin film) to 200ppm/ C	Affects stability over temperature
Operating Temp	-55 C to +155 C	Defines environmental reliability
Voltage Coefficient	<0.1ppm/V	Ensures voltage stability

5. Application Fields

Consumer Electronics: Smartphones, wearables, IoT devices
Automotive: ADAS sensors, battery management systems, ECUs
Industrial: PLCs, motor drives, power converters
Telecom: 5G base stations, optical transceivers
Medical: Diagnostic equipment, implantable devices

6. Leading Manufacturers and Products

Manufacturer	Representative Series	Key Features
Yageo	CRCW Series	0.05W-1W, 0.1% tolerance
Vishay	CRCWE Series	Thin film, TCR 25ppm/ C
ROHM	MCR Series	Power resistors up to 2W
Ohmite	PWR Series	High-power 3W devices
Bourns	CRCU Series	Network resistors with 8-element arrays

7. Selection Recommendations

Consider: - Required resistance tolerance and power rating - Operating temperature range (automotive needs -40 C to +125 C) - Package size constraints (e.g., 0402 for mobile devices) - Long-term stability requirements (medical applications prefer thin film) - Cost vs. performance trade-offs (consumer vs. industrial use) Example: For smartphone power management, select 0603 thick film resistors with 1% tolerance and 125 C rating.

8. Industry Trends

Key trends include: - Miniaturization: Development of 0201 and 01005 packages - Higher precision: Sub-0.01% tolerance thin film resistors - Enhanced thermal management: New materials for power densities >1W/mm - Automotive growth: AEC-Q200 qualified parts for EVs - Smart manufacturing: AI-driven resistor selection tools - Sustainability: Lead-free and halogen-free material adoption