Rainbow Electronics MAX16904 User Manual
General Description
The MAX16904 is a small, synchronous buck converter
with integrated high-side and low-side switches. The
device is designed to deliver 600mA with input voltages
from +3.5V to +28V while using only 25µA quiescent
current at no load. Voltage quality can be monitored by
observing the PGOOD signal. The MAX16904 can operate in dropout by running at 97% duty cycle, making it
ideal for automotive and industrial applications.
The MAX16904 operates at a 2.1MHz frequency, allowing for small external components and reduced output
ripple. It guarantees no AM band interference. SYNC
input programmability enables three frequency modes
for optimized performance: forced fixed-frequency
operation, SKIP mode (ultra-low quiescent current of
25µA), and synchronization to an external clock. The
MAX16904 can be ordered with spread-spectrum frequency modulation, designed to minimize EMI-radiated
emissions due to the modulation frequency.
The MAX16904 is available in a thermally enhanced,
3mm x 3mm, 10-pin TDFN package or a 16-pin TSSOP
package. The MAX16904 operates over the -40°C to
+125°C automotive temperature range.
Applications
Automotive
Industrial
Military
High-Voltage Input-Power DC-DC Applications
Features
o Wide +3.5V to +28V Input Voltage Range
o Tolerates Input Voltage Transients to +42V
o 600mA Minimum Output Current with Overcurrent
Protection
o Fixed Output Voltages (+3.3V and +5V)
o 2.1MHz Switching Frequency with Three Modes of
Operation
25µA Ultra-Low Quiescent Current SKIP Mode
Forced Fixed-Frequency Operation
External Frequency Synchronization
o Optional Spread-Spectrum Frequency Modulation
o Power-Good Output
o Enable-Pin Compatible from +3.3V Logic Level to
+42V
o Thermal Shutdown Protection
o -40°C to +125°C Automotive Temperature Range
o 10-Pin TDFN-EP or 16-Pin TSSOP-EP Packages
o AEC-Q100 Qualified
MAX16904
2.1MHz, High-Voltage,
600mA Mini-Buck Converter
________________________________________________________________
Maxim Integrated Products
1
19-5481; Rev 1; 11/10
EVALUATION KIT
AVAILABLE
PART
SPREAD
SPECTRUM
TEMP
RANGE
PINPACKAGE
MAX16904RATB__/V+ Disabled
-40°C to
+125°C
10 TDFN-EP*
MAX16904RAUE__/V+ Disabled
-40°C to
+125°C
16 TSSOP-EP*
MAX16904SATB__/V+ Enabled
-40°C to
+125°C
10 TDFN-EP*
MAX16904SAUE__/V+ Enabled
-40°C to
+125°C
16 TSSOP-EP*
Ordering Information
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Note: Insert the desired suffix letters (from
Selector Guide
) into
the blanks to indicate the output voltage. Alternative output voltages available upon request.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
*
EP = Exposed pad.
Selector Guide appears at end of data sheet.
MAX16904
2.1MHz, High-Voltage,
600mA Mini-Buck Converter
2 _______________________________________________________________________________________
Typical Operating Circuits
5V AT 600mA
3.3V AT 600mA
10μF
10μF
4.7μH
3.3μH
4.7μF
0.1μF
4.7μF
0.1μF
SUP
EN
33kΩ
*
V
BAT
SIGNAL
LEVEL
MAX16904_50/V+
SYNC
BST
LX
PGND
OUTS
SUP
*
GND
PGOOD
BIAS
20kΩ
2.2μF
EN
33kΩ
V
BAT
SIGNAL
LEVEL
MAX16904_33/V+
SYNC
BST
LX
PGND
OUTS
GND
PGOOD
20kΩ
BIAS
2.2μF
*PLACE INPUT SUPPLY CAPACITORS AS CLOSE AS POSSIBLE TO THE SUP PIN. SEE THE APPLICATIONS INFORMATION SECTION FOR MORE DETAILS.
MAX16904
2.1MHz, High-Voltage,
600mA Mini-Buck Converter
_______________________________________________________________________________________ 3
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
SUP
= +14V, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C, unless otherwise noted.)
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.
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial
.
(Voltages referenced to GND.)
SUP, EN..................................................................-0.3V to +42V
BST to LX..................................................................-0.3V to +6V
LX..............................................................-0.3V to (V
SUP
+ 0.3V)
BST .........................................................................-0.3V to +47V
OUTS ......................................................................-0.3V to +12V
SYNC, PGOOD, BIAS............................................-0.3V to +6.0V
PGND to GND .......................................................-0.3V to +0.3V
LX Continuous RMS Current .................................................1.0A
OUTS Short-Circuit Duration ......................................Continuous
ESD Protection
Human Body Model .........................................................±2kV
Machine Model ..............................................................±200V
Continuous Power Dissipation (T
A
= +70°C)
10-Pin TDFN (derate 24.4 mW/°C above +70°C) ..........1951mW
16-Pin TSSOP (derate 26.1 mW/°C above +70°C) ........2089mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 1)
10-Pin TDFN...................................................................9°C/W
16-Pin TSSOP.................................................................3°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 1)
10-Pin TDFN.................................................................41°C/W
16-Pin TSSOP............................................................38.3°C/W
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage Range V
Supply Current I
UV Lockout
Bias Voltage V
Bias Current Limit I
BUCK CONVERTER
Voltage Accuracy
V
UVLO,HYS
V
V
V
V
SUP
SUP
V
UVLO
BIAS
BIAS
OUT,5V
OUT,3.3V
OUT,5V
OUT,3.3V
(Note 2) 3.5 28
t < 1s 42
EN = low 4 8
EN = high, no load 25 35
EN = high, continuous, no switching 1 mA
Bias rising 2.8 3 3.2
Hysteresi s 0.4
+5.5V V
10 mA
V
= 5V, fixed frequency -2.0% 5 +2.5%
OUT
V
= 5V, SKIP mode
OUT
(Note 3)
V
= 3.3V, fixed frequency -2.0% 3.3 +2.5%
OUT
V
= 3.3V, SKIP mode
OUT
(Note 3)
V
= 5V, fixed frequency -3.0% 5 +2.5%
OUT
V
= 5V, SKIP mode
OUT
(Note 3)
V
= 3.3V, fixed frequency
OUT
V
= 3.3V, SKIP mode
OUT
(Note 3)
+42V 5 V
SUP
6.5V V
I
LOAD
= 0°C to +125°C
T
A
6.5V V
I
LOAD
= -40°C to
T
A
+125°C
18V,
SUP
= 0 to 600mA,
18V,
SUP
= 0 to 600mA,
-2.0% 5 +4%
-2.0% 3.3 +4%
-3.0%
-3.0%
-3.0%
5 +4%
3.3 +2.5%
3.3 +4%
V
μA
V
V
MAX16904
2.1MHz, High-Voltage,
600mA Mini-Buck Converter
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
SUP
= +14V, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C, unless otherwise noted.)
Note 2: When the typical minimum on-time of 80ns is violated, the device skips pulses.
Note 3: Not production tested. Guaranteed by design.
SKIP-Mode Peak Current I
High-Side DMOS RDSON R
Low-Side DMOS RDSON R
DMOS Peak Current-Limit
Threshold
Soft-Start Ramp Time t
LX Ri se Time t
Minimum On-Time tON 80 ns
PWM Switching Frequency fSW Internally generated 1.925 2.1 2.275 MHz
SYNC Input Frequency Range f
Spread-Spectrum Range SS Spread-spectrum option on ly +6 %
PGOOD
PGOOD Threshold
PGOOD Debounce t
PGOOD High Leakage Current I
PGOOD Output Low Level V
LOGIC L E V ELS
EN Le vel
EN Input Current I
SYNC Switching Threshold
SYNC Internal Pulldown R
THERMAL PROTECTION
Thermal Shutdown T
Thermal Shutdown Hysteresis T
PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS
SKIP
V
ON,HS
250 450 m
ON,LS
I
MAX
SS
5 ns
RISE,LX
1.8 2.6 MHz
SYNC
V
V
LEAK,PGD
OUT,PGD
V
V
PD,SYNC
SHDN,HYS
V
THR,P GD
V
THF,PGD
10 μs
DEB
TA = +25°C 1 μA
Sinking 1mA 0.4 V
V
2.4
IH,EN
0.6
V
IL, EN
VEN = V
IN,EN
1.4
IH,SYNC
0.4
IL, SYNC
200 k
175 °C
SHDN
= 5V 400 800 m
BIAS
ris ing 93
OUT
falling 88 91 94
OUT
= +42V, TA = +25°C 1 μA
SUP
15 °C
350 mA
850 1500 1725 mA
7 8 9 ms
%
V
V
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