Datasheet

MAX16993 Step-Down Controller with
Dual 2.1MHz Step-Down DC-DC Converters
www.maximintegrated.com
Maxim Integrated │ 10
Pin Description (continued)
PIN NAME FUNCTION
12 CS1
Positive Current-Sense Input for Buck 1. Connect CS1 to the positive terminal of the current-sense resistor.
See the Current-Limit/Short-Circuit Protection and Current-Sense Measurement sections.
13 OUT1
Output Sense and Negative Current-Sense Input for Buck 1. The buck uses OUT1 to sense the output
voltage. Connect OUT1 to the negative terminal of the current-sense resistor.
See the Current-Limit/Short-Circuit Protection and Current-Sense Measurement sections.
14 EN2 Active-High Digital Enable Input for Buck 2. Driving EN2 high enables Buck 2.
15 EN3 Active-High Digital Enable Input for Buck 3. Driving EN3 high enables Buck 3.
16 OUT3
Buck Converter 3 Voltage-Sense Input. Connect OUT3 to the output of Buck 3. Connect OUT3 to an external
feedback divider when setting DC-DC3 voltage externally. See the OUT2/OUT3 Adjustable Output-Voltage
Option section.
17 RESET3
Open-Drain Buck 3 Reset Output. RESET3remainslowforaxedtimeaftertheoutputofBuck3has
reached its regulation level (see the Selector Guide). To obtain a logic signal, pull up RESET3 with an
external resistor connected to a positive voltage lower than 5V.
18 PV3 Buck 3 Voltage Input. Connect a 2.2µF or larger ceramic capacitor from PV3 to PGND3. Connect PV3 to OUT1.
19 LX3 Buck 3 Switching Node. LX3 is high impedance when the device is off.
20 PGND3 Power Ground for Buck 3
21 PGND2 Power Ground for Buck 2
22 LX2 Buck 2 Switching Node. LX2 is high impedance when the device is off.
23 PV2 Buck 2 Voltage Input. Connect a 2.2µF or larger ceramic capacitor from PV2 to PGND2. Connect PV2 to OUT1.
24 RESET2
Open-DrainBuck2ResetOutput.ThisoutputremainslowforaxedtimeaftertheoutputofBuck2has
reached its regulation level (see the Selector Guide). To obtain a logic signal, pull up RESET2 with an
external resistor connected to a positive voltage lower than 5V.
25 OUT2
Buck Converter 2 Voltage-Sense Input. Connect OUT2 to the output of Buck 2. Connect OUT2 to an external
feedback divider when setting DC-DC2 voltage externally. See the OUT2/OUT3 Adjustable Output-Voltage
Option section.
26 CSEL1
Buck 1 Clock Select. Connect CSEL1 to GND for 2.1MHz operation. Connect CSEL1 to BIAS for an OTP-
programmable divide-down operation. See the Selector Guide for the f
SW1
divide ratio.
27 SSEN
Spread-Spectrum Enable. Connect SSEN to GND for standard oscillator operation. Connect SSEN to BIAS to
enable the spread-spectrum oscillator.
28 RESET1
Open-Drain Buck 1 Reset Output. RESET1remainslowforaxedtimeaftertheoutputofBuck1has
reached its regulation level (see the Selector Guide). To obtain a logic signal, pull up RESET1 with an
external resistor connected to a positive voltage lower than 5V.
29 GND Analog Ground
30 COMP1 Compensation for Buck 1. See the Compensation Network section.
31 ERR
Open-Drain Error-Status Output. ERR signals a thermal-warning/shutdown condition. To obtain a logic signal,
pull up ERR with an external resistor connected to a positive voltage lower than 5V.
32 SYNC
Synchronization Input. SYNC allows the device to synchronize to other supplies. Connect SYNC to GND or
leave unconnected to enable skip-mode operation under light loads. Connect SYNC to BIAS or an external
clocktoenablexed-frequencyforced-PWM-modeoperation.
— EP
Exposed Pad. Connect the exposed pad to ground. Connecting the exposed pad to ground does not remove
the requirement for proper ground connections to PGND2–PGND3 and GND. The exposed pad is attached
with epoxy to the substrate of the die, making it an excellent path to remove heat from the IC.