MAX8620YETD+T Maxim Integrated Products, MAX8620YETD+T Datasheet - Page 13

• Manufacturer Part Number: MAX8620YETD+T
• Description: IC UPMIC FOR MPU 14-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8620YETD+T

• Applications: Micro-Power Management Integrated Circuit (UPMIC), DSPs
• Voltage - Input: 2.7 ~ 5.5 V
• Number Of Outputs: 3
• Voltage - Output: 0.6 ~ 3.3 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN Exposed Pad
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 45 C
• Output Current: 500 mA
• Output Voltage: 0.6 V to 3.3 V
• Supply Current: 115 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

If a long-key press is preferred, see
must remain high until a microprocessor asserts a logic-
high signal when using this circuit. If a system includes
multiple power-on sources, use a diode OR configura-
tion, as shown in Figure 7.
Figure 6. Long-Key Power-On Closed Loop
Figure 7. Multiple Power-On Inputs
Select a step-down converter output voltage between
0.6V and 3.3V by connecting a resistor voltage-divider
between LX, FB, and GND (see Figure 2). The FB bias
HANDS-FREE KIT
AC ADAPTER
POWER-ON
Setting the Step-Down Output Voltage
KEY
POWER-ON
KEY
1MΩ
1MΩ
______________________________________________________________________________________
PWR_ON
POWER-HOLD SIGNAL
HF_PWR
PWR_ON
MAX8620Y
POWER-HOLD SIGNAL
MAX8620Y
µPMIC for Microprocessors or DSPs
Figure 6. PWR_ON
V
V
V
CORE
I/O
ANA
V
V
V
CORE
I/O
ANA
PWR HOLD
(OUT3)
PWR HOLD
µP
µP
current, I
divider bias current dominates I
wide range of resistor values is acceptable, but a good
starting point is to choose R2 = 100kΩ. R1 is given by:
where V
V
down converter dropout voltage and inductor voltage
drop impact how close V
dropout voltage is a function of the pFET on-resistance,
the DCR of the inductor, and the load as follows:
For example, with 300mA load:
As a result, V
V
The MAX8620Y step-down converter operates with induc-
tors between 1µH and 4.7µH. Low inductance values are
physically smaller but require faster switching, which
results in some efficiency loss. See the Typical Operating
Characteristics section for efficiency and switching fre-
quency versus inductor value plots. The inductor’s DC
current rating needs to be only 100mA greater than the
application’s maximum load current because the
MAX8620Y step-down converter features zero-current
overshoot during startup and load transients.
For output voltages above 2.0V, when light-load effi-
ciency is important, the minimum recommended induc-
tor is 2.2µH. For optimum voltage-positioning load
transients, choose an inductor with DC series resis-
tance in the 50mΩ to 150mΩ range (Table 3). For high-
er efficiency at heavy loads (above 200mA) or minimal
load regulation (but some transient overshoot), the
resistance should be kept below 100mΩ. For light-load
applications up to 200mA, much higher resistance is
acceptable with very little impact on performance.
OUT3
OUT3
in Portable Equipment
V
V
OUT DO
OUT DO
by 210mV to maintain regulation.
can be set between 0.6V and 3.3V, but the step-
FB
FB
3
3
(
= 0.6V.
(
, is typically 10nA. Select R2 so the resistor-
)
)
IN1
=
=
300
R
I
OUT
1
= V
=
mA
R
3
2
IN2
×
×
⎛
⎜
⎝
(
(
OUT3
R
V
0 65
must exceed the desired
OUT
V
ONP
.
FB
Inductor Selection
Ω
FB
3
can be to V
+
+
−
DCR
1
by a factor of 10. A
50
⎞
⎟
⎠
m
INDUCTOR
Ω
)
=
210
IN2
mV
. Total
)
13