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MAX8620
User Manual
18 pgs419.03 Kb0

Rainbow Electronics MAX8620 User Manual

General Description
The MAX8620Y micro-power-management integrated circuit (µPMIC) powers low-voltage microprocessors or DSPs in portable devices. The µPMIC includes a high­efficiency step-down DC-DC converter, two low­dropout linear regulators (LDOs), a microprocessor reset output, and power-on/off control logic. This device maintains high efficiency at light loads with a low 115µA supply current, and its miniature TDFN package makes it ideal for portable devices.
The MAX8620Y’s step-down DC-DC converter utilizes a proprietary 4MHz hysteretic-PWM control scheme that allows for ultra-small external components. Internal syn­chronous rectification improves efficiency and elimi­nates the external Schottky diode that is required in conventional step-down converters. The output voltage is adjustable from 0.6V to 3.3V, with guaranteed output current up to 500mA.
The MAX8620Y’s two LDOs offer low 45µV
RMS
output noise and a low dropout of only 200mV at 200mA. Each LDO delivers at least 300mA of continuous output cur­rent. The output voltages are pin selectable from 1.8V to 3.3V for flexibility.
A microprocessor reset output (RESET) monitors OUT1 and warns the system of impending power loss allow­ing safe shutdown. RESET asserts during power-up, power-down, shutdown, and fault conditions where V
OUT1
is below its regulation voltage.
Applications
Cellular Handsets
Smart Phones/PDA Phones
PDAs
Wireless LAN
Microprocessor and DSP Solutions including MSM™, XScale™, ARM™, and OMAP™
Features
♦ Three Regulators and a Reset in One Package
♦ High-Efficiency Step-Down Converter
Up to 4MHz Fixed Switching Frequency 500mA Guaranteed Output Current
0.6V to 3.3V Adjustable Output Voltage ±2% Initial Accuracy Fast Voltage-Positioning Transient Response Internal Synchronous Rectifier
♦ Two 300mA LDO Regulators
200mV Dropout at 200mA Load Low 45µV
RMS
Output Noise 3% Accuracy over Line, Load, and Temperature Overcurrent Protection Nine Pin-Selectable Output-Voltage Settings
♦ 30ms (min) RESET Output Flag
♦ 2.7V to 5.5V Input
♦ 115µA (typ) Supply Current at No Load
♦ Thermal-Overload Protection
♦ Tiny 3mm x 3mm x 0.8mm TDFN Package
MAX8620Y
µPMIC for Microprocessors or DSPs
in Portable Equipment
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
Typical Operating Circuit
19-3564; Rev 0; 1/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MSM is a trademark of QUALCOMM, Inc. XScale is a trademark of Intel Corp. ARM is a trademark of ARM Limited. OMAP is a trademark of Texas Instruments, Inc.
EVALUATION KIT
AVAILABLE
Pin Configuration appears at end of data sheet.
PART TEMP RANGE
MAX8620YETD -40°C to +85°C
PIN­PACKAGE
14 TDFN-EP (T1433-2)
TOP
MARK
AAB
V
OUT1
V
LOGIC
AND V
100kΩ
1.80V, 2.60V, 2.80V, 2.85V,
3.00V, OR 3.30V* 300mA
1.80V, 2.50V, 2.60V,
2.85V, OR 3.00V* 300mA
RESET
OUT2
IN
IN2
IN1
MAX8620Y
BP
EN2
HF_PWR
PWR_ON
SEL1
SEL2
GND
*USE SEL1 AND SEL2 TO SET V
OUT1
OUT2
RESET
LX
FB
OUT3
0.6V TO 3.3V 500mA
MAX8620Y
µPMIC for Microprocessors or DSPs in Portable Equipment
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN1
= V
IN2
= +3.7V, CIN= 10µF, CBP= 0.01µF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
IN1, IN2, PWR_ON, RESET, EN2, SEL1, SEL2,
HF_PWR, FB, BP to GND ..................................-0.3V to +6.0V
OUT1, OUT2 to GND .................................-0.3V to (V
IN1
+ 0.3V)
LX Current ......................................................................1.5A
RMS
Continuous Power Dissipation (TA= +70°C)
14-Pin TDFN (derate 18.2mW/°C above +70°C) .......1454mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage Range V
IN1
2.7 5.5 V
Shutdown Supply Current I
SHDN
V
IN1
= V
IN2
= 4.2V, PWR_ON = HF_PWR =
GND
5.5 10 µA
All outputs enabled, no load
140
Supply Current
V
OUT1
= V
OUT3
= 1.8V, I
OUT1
= I
OUT3
=
500µA, OUT2 disabled
µA
UNDERVOLTAGE LOCKOUT
V
IN1
= V
IN2
rising
UVLO Threshold V
UVLO
V
IN1
= V
IN2
falling
V
THERMAL PROTECTION
Thermal-Shutdown Threshold Temperature rising
°C
Thermal-Shutdown Hysteresis 15 °C
REFERENCE (BP)
Reference Bypass Output Voltage
V
BP
0 ≤ IBP ≤ 1µA
V
LOGIC AND CONTROL INPUTS (PWR_ON, HF_PWR, EN2)
PWR_ON, HF_PWR, EN2 Input Low Voltage
V
IL
V
IN1
= V
IN2
= 2.7V to 4.2V (Note 2) 0.4 V
PWR_ON, HF_PWR, EN2 Input High Voltage
V
IH
V
IN1
= V
IN2
= 2.7V to 4.2V (Note 2)
V
Input Bias Current I
INB
V
PWR_ON
= V
HF_PWR
= V
EN2
= 0V or 5.5V -1 +1 µA
HF_PWR Timer t
HF
From the rising edge of HF_PWR until the one-shot timer expires (Figure 4)
s
LINEAR REGULATORS (OUT1, OUT2)
0°C to +85°C
I
LOAD
= 1mA, 3.7V ≤ V
IN
≤ 5.5V
-40°C to +85°C
1mA ≤ I
LOAD
≤ 300mA
OUT1, OUT2 Output-Voltage Accuracy
V
OUT2
I
LOAD
= 150mA 0
%
OUT1, OUT2 Output Current I
OUT_
mA
OUT1, OUT2 Output Current Limit
I
LIM_
V
OUT_
= 0V
940 mA
OUT1, OUT2 Dropout Voltage V
DO
I
LOAD
= 200mA, TA = +85°C (Note 3)
380 mV
I
+ I
IN1
IN2
,
V
OUT1
115
430
2.70 2.85 3.05
2.35
+160
1.231 1.250 1.269
1.44
1.05 1.31 1.46
-1.3 +1.8
-1.5 +1.8
-1.2
300
310 550
200
MAX8620Y
µPMIC for Microprocessors or DSPs
in Portable Equipment
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1
= V
IN2
= +3.7V, CIN= 10µF, CBP= 0.01µF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 1)
Note 1: Specifications are 100% production tested at T
A
= +25°C. Maximum and minimum limits over temperature are guaranteed
by design and characterization.
Note 2: After startup. Note 3: Guaranteed by design. Note 4: RESET asserts low when V
OUT1
drops below the specified percent of the OUT1 regulation voltage.
OUT1, OUT2 Power-Supply Rejection Ratio
Output Noise Voltage
STEP-DOWN CONVERTER (OUT3)
Output Voltage Range V
FB Threshold Voltage V
FB Threshold Line Regulation V
FB Threshold Voltage Accuracy (Falling) (% of V
FB Threshold Voltage Hysteresis (% of V
FB Bias Current I
Current Limit
On-Resistance
Rectifier-Off Current Threshold I
Minimum On- and Off-Times
OPEN-DRAIN, ACTIVE-LOW RESET OUTPUT (RESET)
RESET Output-Voltage Low V RESET Output Leakage Current V
RESET Threshold Voltage V
RESET Timeout Period t
LDO OUTPUT-VOLTAGE SELECT INPUTS (SEL1, SEL2)
SEL_ Input Low Threshold 1V
SEL_ Input High Threshold V
SEL_ Input Bias Current
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
TH
f = 10Hz to 10kHz, C
= 30mA
I
LOAD_
f = 100Hz to 100kHz, C
= 30mA
I
LOAD_
f = 100Hz to 100kHz, C
= 30mA, CBP open
I
LOAD_
OUT3
VFB falling 0.6 V
TH
= V
IN1
I
)
TH
V
)
HYS
FB
I
LIM3P
I
LIM3N
R
ONP
R
ONN
LXOFF
t
ON
t
OFF
OL
THR
RP
OUT3
OUT3 disabled 10
V
FB
pFET switch 675 950 1200
nFET rectifier 875 1000 1200
pFET switch, I
nFET rectifier, I
I
SINK
RESET
Percent of the OUT1 regulation voltage (Note 4)
Figure 4 30 60 ms
V
IN1
V
SEL2
= 2.7V to 5.5V (Note 2) 0.08 %/V
IN2
= 0mA
= 0.5V 10
= -200mA 0.65 1.5
LX
= +200mA 0.35 0.8
LX
= 500µA 0.3 V
= 5.5V 100 nA
= V
= 4.2V, V
IN2
= 0V or V
IN1
= 4.7µF,
OUT_
OUT_
OUT_
= 4.7µF,
= 4.7µF,
60 dB
45
100
0.6 3.3 V
TA = +25°C -2 +2
= -40°C to +85°C -3 +3
T
A
2%
30 60 mA
107
95
84 87 90 %
- 0.2V V
IN_
SEL1
= 0V or V
IN1
,
±0.1 µA
µV
RMS
%
µA
mA
Ω
ns
MAX8620Y
µPMIC for Microprocessors or DSPs in Portable Equipment
4 _______________________________________________________________________________________
Typical Operating Characteristics
(V
IN1
= V
IN2
= 3.7V, PWR_ON = IN1, L = 2.2µH (LQH31CN2R2M53), CFF= 150pF, V
OUT1
= V
OUT2
= 2.6V, V
OUT3
= 1.867V (R1 =
150kΩ, R2 = 75kΩ), C
IN
= 10µF, C
BP
= 0.01µF, C
OUT1
= C
OUT2
= 4.7µF, C
OUT3
= 2.2µF, RESET pulled up with 100kΩ to OUT1,
T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
MAX8620Y toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
100101
10
20
30
40
50
60
70
80
90
100
0
0.1 1000
L = 4.7µH
L = 2.2µH
L = 1.0µH
INPUT QUIESCENT CURRENT
vs. INPUT VOLTAGE
MAX8620Y toc02
INPUT VOLTAGE (V)
QUIESCENT CURRENT (µA)
5.04.53.5 4.03.02.5
20
40
60
80
100
120
140
160
180
0
2.0 5.5
SWITCHING FREQUENCY vs. LOAD CURRENT
SWITCHING FREQUENCY (MHz)
45040035030025020015010050
1
10
0.1 0 500
MAX8620Y toc03
LOAD CURRENT (mA)
L = 4.7
µH
L = 2.2µH
L = 1.0µH
EFFICIENCY vs. OUTPUT VOLTAGE
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
2.42.20.8 1.0 1.2 1.6 1.81.4 2.0
65
70
75
80
85
90
95
100
60
0.6 2.6
MAX8620Y toc04
L = 4.7µH
L = 2.2µH
L = 1.0µH
LIGHT-LOAD SWITCHING WAVEFORMS
MAX8620Y toc05
200ns/div
I
L
V
OUT
AC-COUPLED
2V/div
20mV/div
100mA/div
V
LX
HEAVY-LOAD SWITCHING WAVEFORMS
MAX8620Y toc06
200ns/div
I
L
V
OUT
AC-COUPLED
2V/div
20mV/div
200mA/div
V
LX
MAX8620Y
µPMIC for Microprocessors or DSPs
in Portable Equipment
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(V
IN1
= V
IN2
= 3.7V, PWR_ON = IN1, L = 2.2µH (LQH31CN2R2M53), CFF= 150pF, V
OUT1
= V
OUT2
= 2.6V, V
OUT3
= 1.867V (R1 =
150kΩ, R2 = 75kΩ), C
IN
= 10µF, C
BP
= 0.01µF, C
OUT1
= C
OUT2
= 4.7µF, C
OUT3
= 2.2µF, RESET pulled up with 100kΩ to OUT1,
T
A
= +25°C, unless otherwise noted.)
LOAD TRANSIENT (50mA TO 300mA)
MAX8620Y toc07
2µs/div
I
L
I
LOAD
V
OUT3
AC-COUPLED
50mV/div
200mA/div
300mA
50mA
200mA/div
POWER-UP WAVEFORMS
MAX8620Y toc08
40µs/div
V
OUT3
V
OUT1
V
OUT2
V
IN
2V/div
1V/div
1V/div
1V/div
PWR_ON STARTUP/SHUTDOWN WAVEFORMS
MAX8620Y toc09
100µs/div
V
OUT3
V
OUT1
V
OUT2
V
PWR_ON
2V/div
1V/div
1V/div
1V/div
RESET WAVEFORMS
MAX8620Y toc10
10ms/div
V
OUT1
V
PWR_ON
2V/div
1V/div
1V/div
V
RESET
OUT2 SHUTDOWN WAVEFORMS
MAX8620Y toc11
200µs/div
V
OUT2
V
EN2
1V/div
1V/div
HF_PWR STARTUP WAVEFORMS
MAX8620Y toc12
10ms/div
V
OUT1
V
HF_PWR
1V/div
2V/div
1V/div
V
RESET
MAX8620Y
µPMIC for Microprocessors or DSPs in Portable Equipment
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
IN1
= V
IN2
= 3.7V, PWR_ON = IN1, L = 2.2µH (LQH31CN2R2M53), CFF= 150pF, V
OUT1
= V
OUT2
= 2.6V, V
OUT3
= 1.867V (R1 =
150kΩ, R2 = 75kΩ), C
IN
= 10µF, C
BP
= 0.01µF, C
OUT1
= C
OUT2
= 4.7µF, C
OUT3
= 2.2µF, RESET pulled up with 100kΩ to OUT1,
T
A
= +25°C, unless otherwise noted.)
OUT1/OUT2 VOLTAGE vs. INPUT VOLTAGE
2.80
2.75
2.70
2.65
2.60
2.55
2.50
OUTPUT VOLTAGE (V)
2.45
2.40
2.35
2.30
3.0 5.5
OUT1/OUT2 LOAD REGULATION vs. LOAD CURRENT
-0.1
-0.3
-0.5
-0.7
-0.9
LOAD REGULATION (%)
-1.1
-1.3
-1.5 0 300
I
= 0mA
LOAD
I
= 300mA
LOAD
INPUT VOLTAGE (V)
LOAD CURRENT (mA)
DROPOUT VOLTAGE vs. LOAD CURRENT
400
MAX8620Y toc13
5.04.54.03.5
350
300
250
200
150
DROPOUT VOLTAGE (mV)
100
V
50
0
0 300
LOAD CURRENT (mA)
OUT_
MAX8620Y toc14
= 3V
25020050 100 150
OUT1/OUT2 POWER-SUPPLY
RIPPLE REJECTION vs. FREQUENCY
80
MAX8620Y toc15
25020015010050
70
60
50
40
30
20
10
POWER-SUPPLY RIPPLE REJECTION (dB)
0
0.1 1000 FREQUENCY (kHz)
100101
MAX8620Y toc16
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