MAX8819BETI+T Maxim Integrated Products, MAX8819BETI+T Datasheet - Page 23

• Manufacturer Part Number: MAX8819BETI+T
• Description: IC PMIC W/INT CHARGER 28-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8819BETI+T

• Applications: Handheld/Mobile Devices
• Voltage - Supply: 2.6 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

As the load current is increased beyond this point, the
output voltage sags and the converter goes out of regu-
lation because the inductor current cannot increase
above the p-channel peak current limit.
The step-down converter implements short-circuit protec-
tion by monitoring the feedback voltage, V
start, if V
switching frequency to f
reaches the p-channel peak current limit, however, at
one-third the frequency. Therefore, the output and input
currents are reduced to approximately one-third of the
maximum value in response to an output short circuit to
Figure 5b. MAX8819C Enable Logic
EN123
Step-Down Converter Short-Circuit Protection
SYS
EN4
FB_
DC
drops below 0.23V, the converter reduces its
PMIC with Integrated Chargers and Smart
500mV HYST.
400mV HYST.
4.0V RISING
100mV HYST.
6.0V RISING
2.5V RISING
______________________________________________________________________________________
DIE TEMP
+165°C
Power Selector in a 4mm x 4mm TQFN
S
/3. The inductor current still
+
-
-
+
+
+
-
-
64 CYCLE
DELAY
(32μs)
2MHz
BIAS
AND
DCUVLO
OSC
REF
DCOVLO
SYSOK
DT165
FB_
. After soft-
READY
REGON
READY
DCPOK
ground. When the short is removed, the inductor current
raises the voltage on the output capacitor and the step-
down converter resumes normal operation.
RST1 is an active-low, open-drain output that pulls low
to indicate that FB1 is below its regulation threshold.
RST1 goes high 200ms after FB1 reaches its regulation
threshold. RST1 is high-impedance when EN123 is
high. See Figures 6 and 7.
A 50μs blanking delay is provided when FB1 is falling,
so that RST1 does not glitch if the REG1 output voltage
is dynamically adjusted by altering the resistors in its
feedback network.
REGON
MAX8819C
EN
EN
EN
EN
SOFT-START
SOFT-START
SOFT-START
SOFT-START
REG2
REG4
REG1
REG3
OK
OK
OK
OK
REG1 Reset (RST1)
REG1OK
REG2OK
REG3OK
REG4OK
23