MAX1816, MAX1994 Dual Step-Down Controllers Plus Linear-Regulator Controller for Notebook Computers

Description

The MAX1816/MAX1994 are dual step-down controllers for notebook computer applications. BUCK1 is a CPU core regulator with dynamically adjustable output, ultra-fast transient response, high DC accuracy, and high efficiency. BUCK2 is an adjustable step-down regulator for I/O and memory supplies. Both regulators employ Maxim's proprietary Quick-PWM™ control architecture. This fast-response, constant-on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns "instant" on-response to load transients, while maintaining a relatively constant switching frequency. The MAX1816/MAX1994 also have a linear-regulator controller for low-voltage auxiliary power supplies.

The CPU regulator supports "active voltage positioning" to reduce output bulk capacitance and lower power dissipation. A programmable gain amplifier allows the use of lower value sense resistors. Four fixed-gain settings are available (0, 1.5, 2, and 4). A differential remote-sense amplifier is also included to more accurately control the voltage at the load. Accuracy is further enhanced with an internal integrator.

The MAX1816/MAX1994 include a specialized digital interface that makes them suitable for mobile CPU and video processor applications. The power-good (PGOOD) output for the core regulator is forced high during VID transitions, and the LINGOOD output for the linear regulator includes a 1ms (min) turn-on delay.

BUCK1, BUCK2, and the linear regulator feature overvoltage protection (OVP). The detection threshold for BUCK1 is adjusted with an external resistive voltage-divider, while the OVP thresholds for BUCK2 and the linear regulator are fixed. Connecting the OVPSET pin to V_CC disables OVP for BUCK1 and BUCK2, but not the linear regulator.

The MAX1816 features an output-voltage adjustment range from 0.6V to 1.75V. Similarly, the MAX1994 is adjustable from 0.925V to 2.0V, using an alternate VID code set. While in suspend mode, the adjustment range is 0.7V to 1.075V for both the MAX1816 and MAX1994. Both parts are available in 48-pin thin QFN packages.

Key Features

Applications/Uses

Dual Quick-PWM Architecture
±1% V_OUT Accuracy
5-Bit On-Board D/A Converter
+0.60V to +1.75V Output Adjust Range (MAX1816)
+0.70V to +2.00V Output Adjust Range (MAX1994)
Voltage-Positioning Gain and Offset Control
+2V to +28V Battery Input Range
Differential Remote Sense (BUCK1)
Linear-Regulator Controller
200/300/550/1000kHz Switching Frequency
2.2mA (typ) I_CC Supply Current
20µA (max) Shutdown Supply Current
Independent Power-Good Outputs (PGOOD, LINGOOD)

	3- to 4-Cell Li+ Battery to CPU Core Supply
	Memory I/O and VID Supplies
	Mobile CPU Core and Video Processors
	Small Notebook Computers

Key Specifications: Switch-Mode DC-DC Power Supplies

Part Number

Topology

V_IN (min) (V)

V_IN (max) (V)

Number of DC-DC Outputs

Preset V_OUT (V)

Digital/VID Programmed Output

Min. Adjustable V_OUT (V)

Max. Adjustable V_OUT (V)

I_OUT (A)

Operating Current, I_CC (max) (mA)

Fixed Freq/PWM Operation

Operating Freq. (kHz)

Internal Power Switch(es)

Synchronous Rectifier

Package

Smallest Available Package (max w/pins) (mm²)

MAX1816

Step-Down

1.8
2.5

Yes

5.5

3.8

Yes

1000
200
300
550

Yes

THIN QFN/48

MAX1994

See All Switch-Mode DC-DC Power Supplies (421)

Ordering Information

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Devices: 1-8 of 8

MAX1816

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX1816ETM

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877-6*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1816ETM-T

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877-6*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1816ETM+

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877+6*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1816ETM+T

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877+6*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1994

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX1994ETM

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877-6*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX1994ETM-T

-40°C to +85°C

See data sheet

MAX1994ETM+

THIN QFN;48 pin;50 mm²
Dwg: 21-0144F (PDF)
Use pkgcode/variation: T4877+6*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX1994ETM+T

-40°C to +85°C

See data sheet

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