MAX5039EUA+ Maxim Integrated Products, MAX5039EUA+ Datasheet - Page 17

• Manufacturer Part Number: MAX5039EUA+
• Description: IC CNTRLR VOLT TRACK 8-MSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5039EUA+

• Applications: Processor
• Current - Supply: 1.3mA
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

threshold. Follow the guidelines below to program the
UVLO voltage:
1) Determine the V
2) Determine the V
3) Set V
4) Calculate R7 using the equation:
where R8 is typically 10kΩ.
Example: V
set the V
Choose R8 = 10.0kΩ, ±1%:
Use the next-lower value: R7 = 25.5kΩ.
See the application circuit examples in Figures 9 and 10.
The external MOSFET, together with the feedback resis-
tor-divider, R1 and R2, from CORE to CORE_FB to GND,
and NDRV form a linear regulator loop. This linear regu-
lator should be compensated for stable operation.
Note: The linear regulator spends most of its time in idle
mode. It operates in transient mode and regulation mode
only during system power-up/power-down, brownout,
and occasional system load transient conditions. Loop
stability applies when the linear regulator is in the regula-
R
7
Undervoltage lockout rising trip threshold, V
tolerance: 1.230V ±2.5%
Programming resistor tolerance: pick a ±1% resistor
or better (±1.6% over temperature from Table 1)
Resistor-divider ratio tolerance: ±1% maximum for
±1% resistors
Resistor value resolution: ±0.5% (can be zero if
exact resistor value is available)
Extra margin: ±1%
Total = ±6.6%
V
ance)
=
IN



V
nominal value - (V
UVLO
UVLONOM
UVLO
V
UVCC
IN
nominal value = 5V, V
nominal value to 5V - (5% + 6.6%) = 4.42V.
nominal value to:
Linear Regulator Compensation
R
7
______________________________________________________________________________________
−
=
IN
UVLO
1 8






tolerance; ±5% is common.
V
R
UVLONOM
V
rising threshold tolerance:
=
UVCC



IN
1 230
4 42
.
.
tolerance + V
V
V
−
1 8
IN
−



1 10
R
tolerance = ±5V%;



Voltage-Tracking Controllers for
k
Ω
=
UVLO
25 93
.
UVCC
toler-
PowerPC, DSPs, and ASICs
k
Ω
,
tion mode. Follow these simple guidelines to stabilize the
linear loop: (see the Core Regulator Loop Bode Plot in
the Typical Operating Characteristics).
1) Place C1, a 100nF ceramic capacitor (X5R, X7R
2) Select R1 and R2, a resistor-divider from CORE
3) Place R3 and C2, an RC network from CORE_FB
4) Place R4, a preload resistor, from CORE to
5) Place R9 and C3, a lead network, from V
Example: CORE power supply = 1.8V, V
1.6V, C
Siliconix):
Use a 1.5nF standard value.
Use a 51Ω standard value.
C
3
type or better) from NDRV to GND.
to CORE_FB to GND to set the linear regulator
output regulation voltage (see the Programming
Core Voltage section).
to NDRV. Set R3 = R1 and calculate C2 as follows:
GND.
Calculate R4 as follows:
to CORE_FB. Set R9 = R1/10, and calculate C3
as follows:
=
2
CORE
π
C
×
2
C
7227
R
=
3
C
4
R1 = R3 = 10.0kΩ, 1%
(
2
1
= 100µF, Q
2
=
≤
Hz R
=
π
R
×
2
2
4
0 03
×
10
π
π
1 6
.
×
≤
.
kHz
×
5
10
V
A
1
V
=
7227
0 03
kHz R
1
CORE
.
2
×
π
=
10
1
1
×
A
×
Hz
k
53
7227
Ω
= Si9428 (Vishay
3
Ω
)
×
1
=
Hz
R
1 6
.
9
×
nF
1
k
REGNOM
Ω
CORE
=
22
nF
17
=