MAX5024 MAXIM [Maxim Integrated Products], MAX5024 Datasheet - Page 10

• Manufacturer Part Number: MAX5024
• Description: 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with ?P Reset and Watchdog Timer
• Manufacturer: MAXIM [Maxim Integrated Products]

Select preset voltage mode by connecting SET to
ground. In adjustable mode, select an output between
+2.5V and +11V using two external resistors connected
as a voltage-divider to SET (Figure 4). Set the output
voltage using the following equation:
where V
The MAX5023/MAX5024 high-voltage regulator pro-
vides up to 150mA of output current. The input voltage
extends to +65V. Package power dissipation limits the
amount of output current available for a given input/
output voltage and ambient temperature. Figure 5
depicts the maximum power dissipation curve for these
devices. The graph assumes that the exposed metal
back of the MAX5023/MAX5024 package is soldered to
1in
Use Figure 5 to determine the allowable package dissi-
pation for a given ambient temperature. Alternately, use
the following formula to calculate the allowable pack-
age dissipation:
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with µP Reset and Watchdog Timer
Table 1. Truth Table for Regulator Output
State
X = Don’t care.
10
ORDER
P
D
2
1
2
3
4
5
=
of PC board copper.
______________________________________________________________________________________



 
1 538
1 538
.
.
SET
Available Output Current Calculation
High
High
Low
Low
EN
W for T
X
= 1.248V and R2 ≅ 100kΩ.
- 0.01923 T -
V
OUT
HOLD
High
Low
Low
X
X
A
= V
≤ +
(
70
A
SET
OUT
Off
On
On
On
Off
°
C
70
(1 + R1 / R2)
°
C for
Initial state. EN has 5MΩ
internal resistor to ground.
HOLD has internal current
source to OUT.
Regulator output is active
when EN is pulled high.
Hold is asserted forcing the
regulator output on even if
EN goes low.
S el f- hol d i ng state. Reg ul ator
outp ut stays on r eg ar d l ess of
the state of E N .
Regulator output is
shutdown by releasing
HOLD while EN remains low.
)
+
COMMENTS
70
° <
C
T
A
≤ +
125
°
C
After determining the allowable package dissipation,
calculate the maximum output current using the follow-
ing formula:
The above equations do not include the negligible
power dissipation from self-heating due to the IC
ground current.
Figure 4. Setting the MAX5024 Adjustable Output Voltage
Figure 5. Maximum Power Dissipation vs. Temperature
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
OFF
ON
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
+6.5V TO +65V
I
TO µP
OUT MAX
1.538W
(
10µF
)
V
V
R2 = 1kΩ TO 500kΩ
OUT
SET
IN
EN
RESET
≅
= 1.248V
V
= V
IN
MAX5024
SET
GND
- V
P
T
(1 + R1 / R2)
A
D
(°C)
OUT
HOLD
OUT
SET
≤
150
19.23mW/°C
+2.5V TO +11V
mA
DERATE
R1
R2
15µF