IRF7901D1 Datasheet, PDF (4/8 Pages) International Rectifier – Dual FETKY™ Co-Packaged Dual MOSFET Plus Schottky Diode

IRF7901D1
Typical Application (Contd.)
The Dual FETKY integrates all the power semiconductor devices for DC-DC conversion within one SO-8
package, as shown on page 1. The high side control MOSFET (Q1) is optimized for low combined Q_sw and
R_DS(on). The low side synchronous MOSFET (Q2) is optimized for low R_DS(on) and high Cdv/dt immunity. The
ultra-low V_f schottky diode is internally connected in parallel with the synchronous MOSFET, for improved
deadtime efficiency. For ease of circuit board layout, the Dual FETKY has been internally configured such that
it represents a functional block for the power device portion of the synchronous buck DC-DC converter. This
helps to minimize the external PCB traces compared to a discrete solution.
In-Circuit Efficiency
The in-circuit efficiency curves for the Dual FETKY are shown in Figure 2 & 3. The Dual FETKY can
achieve up to 96.6% and 94.6% peak efficiency for the 5.0V and 3.3V applications respectively, with
excellent maximum load efficiency.
IRF7901D1 Dual FETKY^TM performance in Synchronous Buck
DC-DC for 3.3Vout & 5.0Vout @ 300kHz, using IRNBPS2 design kit
97%
95%
93%
91%
10.8Vin / 3.3Vout
14Vin / 3.3Vout
21Vin / 3.3Vout
10.8Vin / 5.0Vout
14Vin / 5.0Vout
21Vin / 5.0Vout
89%
1
1.5
2
2.5
3
3.5
4
4.5
5
Output Current (A)
IRF7901D1 Dual FETKY^TM performance in Synchronous Buck
DC-DC for 1.0Vout @ 300kHz, using IRNBPS2 design kit
90%
88%
86%
84%
82%
80%
78%
76%
8.4Vin / 1.0Vout
74%
14Vin / 1.0Vout
72%
70%
1.5
2
2.5
3
3.5
4
4.5
5
Output Current (A)
Figure 2. IRF7901D1 Dual FETKY^TM electrical efficiency
at 3.3Vout & 5.0Vout.
Figure 3. IRF7901D1 Dual FETKY^TM electrical efficiency
at 1.0Vout.
Q1 - Control FET
2.0
ID = 5.0A
VGS = 4.5V
1.5
Typical Characteristics
Q2 - Synchronous FET & Schottky
1.50
ID = 5.0A
VGS = 4.5V
1.25
1.0
1.00
0.5
-60 -40 -20 0 20 40 60 80 100 120 140 160
TJ , Junction Temperature (°C)
Figure 4. Normalized On-Resistance vs Junction
Temperature
4
0.75
-60 -40 -20 0 20 40 60 80 100 120 140 160
TJ , Junction Temperature (°C)
Figure 5. Normalized On-Resistance vs Junction
Temperature
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