Datasheet

Detailed Description
The MAX17491 single-phase gate driver, along with the
MAX8736, MAX8786, or MAX17030 multiphase con-
trollers, provide flexible multiphase CPU core-voltage
supplies. The low driver resistance allows up to 7A out-
put peak current. Each MOSFET driver in the
MAX17491 can drive 3nF capacitive loads with only 9ns
propagation delay and 4ns/8ns (typ) fall/rise times,
allowing operation up to 3MHz per phase. Larger
capacitive loads are allowable but result in longer prop-
agation and transition times. Adaptive dead-time con-
trol prevents shoot-through currents and maximizes
converter efficiency while allowing operation with a vari-
ety of MOSFETs and PWM controllers. An input under-
voltage-lockout (UVLO) circuit allows proper power-on
sequencing.
PWM Input
The drivers for the MAX17491 are disabled—DH and
DL pulled low—if the PWM input remains in the midlevel
window for at least 300ns (typ). Once the PWM signal is
driven high or low, the MAX17491 immediately exits the
low-current shutdown state and resumes active opera-
tion. Outside the shutdown state, the drivers are
enabled based on the rising and falling thresholds
specified in the Electrical Characteristics .
MOSFET Gate Drivers (DH, DL)
The high-side driver (DH) has a 0.9Ω sourcing resis-
tance and 0.7Ω sinking resistance, resulting in 2.2A
peak sourcing current and 2.7A peak sinking current
with a 5V supply voltage. The low-side driver (DL) has a
typical 0.7Ω sourcing resistance and 0.3Ω sinking
resistance, yielding 2.7A peak sourcing current and 8A
peak sinking current. This reduces switching losses,
making the MAX17491 ideal for both high-frequency
and high-output-current applications.
MAX17491
Single-Phase Synchronous MOSFET Driver
_______________________________________________________________________________________ 7
OUTPUT (V
OUT
)
L1
0.36μH
MAX17491
PWM
DH
BST
LX
DL
GND
PAD
PWM
+5V BIAS
SUPPLY
SKIP
SKIP
V
DD
C
BST
0.22μF
C
OUT
2x 330μF
6mΩ
C
IN
2x 10μF
INPUT (V
IN
)
C
VDD
1.0μF
N
L
D
L
N
H
Figure 3. Typical MOSFET-Driver Application Circuit
Table 1. Typical Components
DESIGNATION QTY COMPONENT SUPPLIERS
N
H
1 per phase Siliconix Si4860DY
N
L
1–2 per phase Siliconix Si4336DY
BST Capacitor (C
BST
) 1 per phase 0.1µF or 0.22µF ceramic capacitor
Schottky Diode Optional
3A, 40V Schottky diode
Inductor (L1) 1 per phase 0.36µH, 26A, 0.9mΩ power inductor
Output Capacitors (C
OUT
) 1–2 per phase 330µF, 6mΩ per phase
Input Capacitors (C
IN
) 1–2 per phase 10µF, 25V X5R ceramic capacitors