Datasheet

MAX8576–MAX8579
3V to 28V Input, Low-Cost, Hysteretic
Synchronous Step-Down Controllers
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Detailed Description
The MAX8576–MAX8579 synchronous PWM buck con-
trollers use Maxim’s proprietary hysteretic voltage-
mode control algorithm to achieve fast transient
response without any loop-compensation requirement.
The controller drives a pair of external n-channel power
MOSFETs to improve efficiency and cost. The
MAX8576/MAX8577 contain an internal linear low-
dropout (LDO) regulator allowing the controller to oper-
ate from a single 3V to 28V input supply. The
MAX8578/MAX8579 do not contain the internal LDO
and require a separate supply to power the IC when the
input supply is higher than 5.5V. The MAX8576–
MAX8579 output voltages are adjustable from 0.6V to
0.9 x V
IN
at loads up to 15A.
MAX8576/MAX8577
External Component List
COMPONENTS
QTY
DESCRIPTION/VENDOR PART
NUMBER
C1, C2
2
470µF, 35V aluminum electrolytic
capacitors
Sanyo 35MV470WX
C3
1
10µF, 25V X7R ceramic capacitor
C4
1
0.01µF, 10V X7R ceramic capacitor
C5
1
1µF, 35V X7R ceramic capacitor
C6
1
4.7µF, 6.3V X5R ceramic capacitor
C7, C12
2
0.1µF, 10V X7R ceramic capacitors
C8
1
0.027µF, 25V X7R ceramic capacitor
C9, C10
2
2200µF, 6.3V aluminum electrolytic
capacitors
Rubycon 6.3MBZ2200M10X20
C11
1
0.01µF, 25V X5R ceramic capacitor
C13
1
3300pF, 6.3V X5R ceramic capacitor
D1
1
High-speed diode, 100V, 250mA
Philips BAS316 (SOD-323)
L1
1
1.8µH, 14A, 3.48mΩ
Panasonic ETQP2H1R8BFA
Q1
1
30V, 12.5mΩ (max), SO-8
International Rectifier IRF7821
Q2
1
30V, 3.7mΩ, SO-8
International Rectifier IRF7832
Q3
1
2N7002 SOT-23
R1
1
6.04kΩ ±1% resistor
R2
1
5.11 kΩ ±1% resistor
R3
1
12.4kΩ ±1% resistor
R4
1
1kΩ ±5% resistor
R5
1
20kΩ ±5% resistor
R6
1
2Ω ±5% resistor
R7
1
10Ω ±5% resistor
R8
1
4.7Ω ±5% resistor
MAX8578/MAX8579
External Component List
COMPONENT
QTY
DESCRIPTION/VENDOR PART
NUMBER
C14
1
10µF, 25V X5R ceramic capacitor
C15
1
1µF, 25V X5R ceramic capacitor
C16
1
4700pF, 10V X7R ceramic capacitor
C17
1
4.7µF, 6.3V X5R ceramic capacitor
C18
1
0.1µF, 10V X7R ceramic capacitor
C19
1
0.01µF, 25V X7R ceramic capacitor
C20
1
47µF, 6.3V, ESR = 5mΩ, ceramic
capacitor
Taiyo Yuden JMK432476MM
C21
1
0.01µF, 25V X5R ceramic capacitor
C22
0
Optional (47µF, 6.3V, ESR = 5mΩ
ceramic capacitor
Taiyo Yuden JMK432476MM)
C23
1
1000pF, 25V X5R ceramic capacitor
D2
1
High-speed diode, 100V, 250mA
Philips BAS316 (SOD-323)
L2
1
2.2µH, 7.3A, 9.8mΩ
Sumida CDEP104L-2R2
Q4
1
30V, 18mΩ (max), SO-8
International Rectifier IRF7807Z
Q5
1
30V, 9.5mΩ, SO-8
International Rectifier IRF7821
R9
1
6.04kΩ ±1% resistor
R10
1
2.49kΩ ±1% resistor
R11
1
12.4kΩ ±1% resistor
R12
1
2Ω ±5% resistor
R13
1
4.7Ω ±5% resistor