1. Fairchild Low-Side Gate Drivers
FAN31xx & FAN32xx Series
Fairchild Low-Side Gate Drivers
High-Speed Low-Side
Gate Drivers
1A to 9A with Flexible Options
to Fit Every Design

2. FAN31xx and FAN32xx High-Speed Low-Side Gate Drivers
Why Use Gate Drivers?
High peak currents (often several amps) are needed to switch MOSFETs efficiently
To amplify limited PWM output current capability of PWM & digital controllers
Remove power dissipation from control ICs
Reduce noise problems
Place near MOSFET to minimize high-current loops
Reduce noise in sensitive control-chip area
Implement features not available in PWMs
Input level shifting
Timing delays
Fairchild’s Low-Side Driver Advantages:
Compound MillerDrive™ Architecture for Strong Gate Drive
Industry’s Smallest Packages:
2x2 mm, 3x3 mm MLP, SOT23-5 and SOIC-8
CMOS, TTL or External Reference Input Thresholds options
Options for Two Inputs per Channel for Design Flexibility
< 20 ns Propagation Delays for > 1 MHz Switching
Low Standby IDD (5 µA) Options (FAN3111)
Fail-Safe Inputs: Output Held Low if No Input Signal is present
20V Abs max, >4kV ESD, and >500mA Reverse Current
−40 to 125 °C Ambient Operating Temperature Range
MillerDriveTM Architecture

3. FAN3xxx High-Speed Low-Side Gate Drivers Product Family
Type
Configuration
Part Num
In. Thres.
Packages
Released
Single 1A
Dual Input (CMOS); Non-Inv (Ext)
FAN3111
CMOS, Ext
SOT23-5, MLP-6
Yes
Single 2A
Dual Input (+ & -)
FAN3100
CMOS, TTL
SOIC-8, MLP-8
Dual Input (+ & -), Programmable CS
FAN3177
TTL
SOIC-8 No
Non-Inv, 3V3LDO
FAN3180
SOT23-5
Q2’11
Dual 2A
Dual Inverting
FAN3216
Dual Non-Inverting
FAN3217
Dual Inverting + Dual Enable
FAN3226
Dual Non-Inverting + Dual Enable
FAN3227
Dual Input (+ & -); Pin 3 GND
FAN3228
Dual Input (+ & -); Pin 8 GND
FAN3229
Dual 4A
FAN3213
FAN3214
FAN3223
FAN3224
FAN3225
Single 9A
Single Inverting + Enable
FAN3121
Single Non-Inverting + Enable
FAN3122
Bridge 2A
20V Bridge Driver + Dual Enables
FAN3268
30V Bridge Driver + Dual Enables
FAN3278
Jan’11
Every current level & input config offers a choice of …
Duals may be connected in parallel
[selection table_LS drivers_ _VN.xls]

4. FAN3111 IC Driver Benefits vs. Discrete Totem Pole Drivers
Can be physically smaller than discrete solutions  highest density designs
Fewer parts
Integrated features can reduce supporting circuitry
Reduce BOM parts count and assembly concerns
Higher reliability, less test time
Less component-level design which often must be customized for different applications
Fast switching (lower loses) from a slow driving signal
Direct translation from TTL logic inputs to higher Vgs
Easier to introduce RC input delay for critical SR timing applications

5. FAN3100 Single 2A Driver
2x2mm MLP-6 (smallest available) and SOT23-5 packages
3A peak sink & source (2.5A sink/1.8A src. at Vdd/2)
CMOS or TTL input thresholds
10ns fall time with 1nF load
Prop delays < 20ns
Under-Voltage Lockout
Dual Inputs offer either polarity
Non-Inverting w/ IN− held LOW
Inverting with IN+ held HIGH
Fail-Safe Inputs: Output held low if no input signal
Non-inverting over inverting

6. FAN3226/7/8/9 Dual 2A Drivers 3x3mm MLP-8 and SOIC-8
Dual 3A-peak sink & source (2.4A sink/1.6A src. at Vdd/2)
CMOS or TTL input thresholds
10ns fall time with 1nF load
Prop delays < 20ns
Under-Voltage Lockout
Industry standard pin-outs
Dual Inverting & dual Non-Inverting with dual Enable
Dual-Input version (2 x FAN3100)
Enable defaults to “ON”
Fail-Safe Inputs: Output held low if no input signal

7. FAN3223/4/5 Dual 4A Drivers 3x3mm MLP-8 and SOIC-8
Dual 5A-peak sink & source (4.3A sink/2.8A src. at Vdd/2)
CMOS or TTL input thresholds
10ns fall time with 2.2nF load
Prop delays < 20ns
Under-Voltage Lockout
Industry standard pin-outs
Dual Inverting & dual Non-Inverting with dual Enable
Dual-Input version
Enable defaults to “ON”
Fail-Safe Inputs: Output held low if no input signal
UVLO

8. FAN3213/14 and FAN3216/17 Dual 4A and Dual 2A Drivers with No Enables
No-Connect instead of Enables for Compatibility
SOIC-8
TTL input thresholds
Prop delays < 20ns
Under-Voltage Lockout
Industry standard pin-outs
Dual Inverting & Dual Non-Inverting
Fail-Safe Inputs: Output held low if no input signal
FAN3223TMX  FAN3213TMX (Dual 4A, Inv)
FAN3224TMX  FAN3214TMX (Dual 4A, NI)
FAN3226TMX  FAN3216TMX (Dual 2A, Inv)
FAN3227TMX  FAN3217TMX (Dual 2A, NI)
FAN3213T
FAN3216T
FAN3214T
FAN3217T

9. FAN3121/2 Single 9A Drivers 3x3mm MLP-8 and SOIC-8
11A peak sink & source (10A/7A sink/source at Vdd/2)
CMOS or TTL input thresholds
19/23ns FT/RT with 10nF load
20ns typical prop delays
Under-Voltage Lockout
Industry standard Inverting and Non-Inv. pin-outs with Enable
Fail-Safe Input: Output held low if no input signal
Enable defaults to “ON”

10. FAN3268/78 Low-Voltage Bridge Drivers 2A Low-Voltage PMOS-NMOS Bridge Drivers
FAN3268: 4.5 V to 18 V Operating Range
FAN3278: 8 V to 27 V Operating Range
Drives High-Side PMOS and Low-Side NMOS for
Battery-Powered Compact Brushless-dc Motor Drives in Industrial, Medical and Automotive applications such as 12-V blower motors.
Two Independent Enable Pins for Design Flexibility
Operation Default to ON if not connected
Suitable with FDD8424H Dual MOSFETs (40 V, 20 A) in 4-lead DPAK
TTL input thresholds
SOIC package
–40°C to +125°C ambient

11. FAN3268 and FAN3278 2A Low-Voltage PMOS-NMOS Bridge Drivers
Fairchild Semiconductor’s FAN3268 and FAN3278 are a special low-voltage high-performance bridge drivers for fan/pump DC motor drive applications with PMOS/NMOS Half-Bridge configuration.
Battery-Powered Compact Brushless-dc Motor Drives in Industrial, Medical and Automotive applications such as 12V blower motors.
Interface between a sensitive PWM or DSP and the MOSFETs. This device also features robust ESD protection
Key Features
TTL input thresholds to provide buffer and level translation functions from logic inputs.
Internal circuitry provides an under-voltage lockout function that prevents the switching if the VDD supply voltage is below the operating level. If an input is left unconnected, internal resistors bias the inputs such that keeps the external MOSFETs OFF.
Included also are two enable pins, a key feature during medical device power-up, that default to ON if not connected.

12. FAN3268 and FAN3278 Typical 3-Phase Blower Motor Application

13. FAN3278 vs. FAN3268 Key Differences
Supply Voltage
27 V Operating Maximum
30 V Absolute Maximum
18 V Operating Maximum
20 V Absolute Maximum
Gate Drive Regulator
Yes, since the maximum operating VDD can be as high as 27 V, the gate voltage to the external MOSFETs is limited to about 13V.
No gate drive regulator needed. The gate drive voltage is VDD and the FAN3268 switches rail-to-rail.
Minimum Operating Voltage
The optimum operating range is 8 V to 27 V. After the IC turns on at about 3.8 V, the output tracks VDD up to the regulated voltage rail of about 11~13 V. Below 8 V of VDD, the FAN3278 operates, but (a) slower and (b) with limited gate drive voltage until it reaches around 8 V.
4.1 V is the UVLO turn-off voltage which is the minimum operating voltage.
Start-up
The IC starts operating approximately at 3.8 V which acts as a loose UVLO threshold. It incorporates a “smart startup” feature where the outputs are held OFF before the IC starts operating.
Has the tight UVLO threshold of 4.5V on / 4.1V off. Incorporates “smart startup” (outputs held OFF before IC is fully operational at the UVLO threshold).
Output Gate Drive Architecture
Standard MOS-based output structure with gate drive clamp feature.
Compound MillerDrive™ architecture in the final output stage to provide a more efficient gate drive current during the Miller plateau stage of the turn-on/turn-off switching transition.
OUTB Gate Drive Current Strength for P-Channel MOSFETs
Optimized for P-channel: The turn-OFF
(1.5 A) is stronger than turn-ON (1.0A).
P-channel turn-ON (2.4A) is stronger than turn-OFF (1.6A).

14. FAN3180 (Product Preview) Low-Side Gate Driver + 3.3V LDO
±3 A Peak Drive Current at VDD = 12 V
+2.5 A/-1.8 A at VOUT = 6 V
Non-inverting Logic Configuration
TTL Input Compatible Threshold
15 ns Typical Prop. Delay Times
9 ns tF/ 13 ns tR with 1nF Load
MillerDrive™ Compound Technology
LDO
3.3 V, 10 mA Output
±1% at 25°C, ±2.5% Total Variation
General
5 V to 18 V Operating Range
200µA Maximum Total Static Supply Current
5-Pin SOT-23 Package
–40°C to 105°C Operation
FAN3180 Samples Available Now

15. Server, Industrial, Comm. Gate Drivers
Released
Server, Industrial, Comm. Gate Drivers
In Development
Planned
Under Consideration
Low-side Gate Drivers
Low-Voltage Bridge Drivers
Specialized Low-Side Gate Drivers
FAN3223-5
Dual 4A
FAN3213/14
Dual 4A – No ENB
FAN3215
Dual 4A
FAN3226-9
Dual 2A
FAN3216/17
Dual 2A – No ENB
FAN3218
FAN3100
Single 2A
Dual 2A with 1INV+1NINV
Single 1A
FAN3111
Single 9A
FAN3121-2
FAN3268
FAN3278
20V Bridge Driver
30V Bridge Driver
FAN3180
LS Driver + 3V3LDO
FAN3247
SmartMeter Disconnect Switch Driver
Existing Release Release + Future 

16. End

17. Additional Material on Low-Side Gate Drivers

18. FAN3xxx High-Speed Low-Side Gate Drivers Common Applications
SMPS topologies with ground-referenced power switches (forward, boost, push-pull, active clamp)
Synchronous rectifiers in SMPS (often multiple high-gate-charge MOSFETs in parallel)
High-Power PFC Gate Drive
Transformer coupled gate drives (high- & low-side switches) & transformer coupled logic-signal transmission
Drive MOSFETs or IGBTs
Used where PWM controllers need assistance:
PWM outputs cannot provide acceptable switching times
PWM cannot dissipate the drive power
Time delays and/or inversions are needed for some switches
Additional control is needed for startup, shutdown or faults
[Fairchild also offers high-side drivers and synchronous Buck drivers]

19. FAN3224 Dual 4A Low-Side Driver
Double-Ended Synchronous Rectification
High Current Outputs; often have paralleled MOSFETs
Half-bridge, Full-bridge topologies (simplified examples shown)
Ground referenced SRs work in center-tapped or current doubler
Used in servers and telecom rectifiers
SRs used in outputs 1-12V (or higher voltages up to 48V)
[SR double_2006_05_05_SM.ppt – 7 slides]

20. FAN3224 and FAN3225 Dual 4A Drivers
Gate Drive Transformers in Phase-Shifted Full-Bridge
Simplified Phase-Shifted Full-Bridge Application Shown
Two Dual Drivers (FAN3225C) & two transformers for Primary-Side Gate Drive
One dual driver (FAN3224T) for Double-Ended Secondary-Side SR Drivers
[SR double_2006_05_05_SM.ppt – 7 slides]

21. FAN3122 Single 9A Low-Side Driver
Current Doubler - Paralleled FETs

22. FAN31xx and FAN32xx Family High-Speed Low-Side Drivers Type
Configuration
Part Num
In. Thres.
Packages
Released
Single 1A
Dual Input (CMOS); Non-Inv (Ext)
FAN3111
CMOS, Ext
SOT23-5, MLP-6
Yes
Single 2A
Dual Input (+ & -)
FAN3100
CMOS, TTL
SOIC-8, MLP-8
Non-Inv, 3V3LDO
FAN3180
TTL
SOT23-5
No, Q1’11
Dual 2A
Dual Inverting
FAN3216
SOIC-8
Dual Non-Inverting
FAN3217
Dual Inverting + Dual Enable
FAN3226
Dual Non-Inverting + Dual Enable
FAN3227
Dual Input (+ & -); Pin 3 GND
FAN3228
Dual Input (+ & -); Pin 8 GND
FAN3229
Dual 4A
FAN3213
FAN3214
FAN3223
FAN3224
FAN3225
Single 9A
Single Inverting + Enable
FAN3121
Single Non-Inverting + Enable
FAN3122
Bridge 2A
20V Bridge Driver + Dual Enables
FAN3268
30V Bridge Driver + Dual Enables
FAN3278
Every current level & input config offers a choice of …
Duals may be connected in parallel
[selection table_LS drivers_ _VN.xls]

23. Low-Side Drivers Primary-Side PWM Applications
Primary PWM drives primary switches and signals SR MOSFETs
Power path in RED
PWM to SR gates path in BLUE
Primary Switch Driver often high/low driver (HV Gate Driver- HVIC)

24. Low-Side Drivers Secondary-Side PWM Applications
Secondary PWM coordinates primary switches and SR Driver
Power path in RED
PWM to SR gate path in BLUE
Higher power SMPS often have bias supply

25. Transformer-Coupled Gate Drive Example
Phase shifted full bridge with secondary-side control
Primary uses two dual drivers and two transformers
Current doubler rectifier in secondary has dual drivers for ground referenced MOSFETs

26. High-Side Drive with a LS DriverQ1
VDD CC
CCS RS R2 Q2 R1 D1 D2 T1
IC1 VS
A practical high-side drive circuit using a low-side driver and a gate-drive transformer. R1 is a bleeder resistor for shutdown; Q2, R2 & D2 form a turn-off speed-up circuit, D1 & CSS are a charge pump to restore the dc level on the secondary, CC is the dc blocking capacitor to keep the transformer from saturating, and RS is a damping resistor. (The driver bypass capacitors are not shown.)

27. Distributed Gate Drive Example

28. Solenoid Relay Driver in Smart Meters
FAN3227TMX Dual 2-A High-Speed Low-Side Driver
High-Current Pulse Drive
Contactor Disconnect

29. What is MillerDrive™?
Compound drive in FAN3xxx Series (left) combines bipolar high current capability with MOSFETs for rail-to-rail operation and high voltage capability
MOSFET-technology drivers (right) are composed of integrated PMOS / NMOS power devices similar to discrete counterparts

30. Current Rating Comparisons for IC Drivers
Compound drivers rate IOUT with VOUT at VDD/2
Reflects current capability during midrange of output swing
FAN322x specs peak current for comparison purposes
MOSFET-based drivers rate current approximately IOUT,PK
MOS-based drivers specify RDS,high or RDS,low when fully enhanced
Actual and rated current is less than I=VDD/RDS,min
In both, current sink/source magnitude is limited by internal design and specified with no external resistance
Average current available from a driver is limited by power dissipation

31. High Speed FAN3100 with 2.2nF load Input 90% to Output 10% < 35 ns
This is faster than many competitor’s propagation delay alone!
MillerDriveTM
Architecture

32. Tight Matching Between Channels
FAN3224 with 4.7nF load
Typically measure < ½ ns difference between channels (waveform distortion is from external parasitics)
Excellent performance with 2 channels paralleled

33. Input Configurations Single-input drivers Dual-input drivers
Inverting or Non-Inverting logic
Enable input for each channel
Dual-input drivers
Non-inverting operation using IN+ (with IN− held low)
Inverting operation using IN− (with IN+ held high)
Enable function can be implemented
Truth table shows logical operation

34. UVLO Operation Output is LOW until Vdd exceeds UVLO turn-on threshold:
GND IN −
IN+
OUT
PWM
FAN
3100
VDD
GND IN −
IN+
OUT
PWM
FAN
3100
Non-Inverting
Configuration
Inverting
Configuration

35. TTL Input Thresholds Translates logic inputs to higher drive voltages
Input threshold compatible with digital controllers
Threshold limits independent of Vdd
Vin,high,min ≥ 2.0 V
Vin,low,max ≤ 0.8 V
[plot fr FAN _TypCharPlots_2007_11_19.xls]
[driver input options_ _MD.ppt]

36. CMOS Input Thresholds CMOS input threshold scales with Vdd
Vth-high  0.6 x Vdd
Vth-low  0.4 x Vdd
Hysteresis approx. 0.2 x Vdd
CMOS input facilitates adding R-C time delays at the input

37. Thank You

38. The Right Technology for Your Success™
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