MCP1700-3302E — 250mA Ultra-Low Quiescent Current (1.6µA) 3.3V LDO Regulator

Overview

The MCP1700-3302E (MCP1700-3302E/TO) is an ultra-low quiescent current CMOS positive low-dropout (LDO) linear voltage regulator manufactured by Microchip Technology. Available in a 3-pin through-hole TO-92 and surface-mount SOT-23 / SOT-89 package, it supplies a fixed $+3.3\text{V}$ DC rail at up to $250\text{ mA}$ with a mere $1.6\ \mu\text{A}$ typical standby quiescent current.

With a typical dropout voltage of only $178\text{ mV}$ at $250\text{mA}$ ( $70\text{ mV}$ at $100\text{mA}$ ) and full stability with small $1.0\ \mu\text{F}$ ceramic MLCC capacitors, the MCP1700 is the gold standard for battery-powered IoT microcontrollers (ESP32 deep sleep, nRF52, ATmega328P, SAMD21, MSP430) running from single-cell Li-ion/LiFePO4 batteries or $3\times\text{AA/AAA}$ alkaline packs where standard linear regulators would otherwise deplete the battery in idle mode.

Quick reference


Regulator Type	Ultra-Low Quiescent CMOS Low-Dropout (LDO) Regulator
Package	TO-92 (3-pin through-hole) / SOT-23 / SOT-89
Output Voltage ( $V_{OUT}$ )	$+3.3\text{ V}$ DC ( $\pm 0.4\%$ typ, $\pm 2.0\%$ max)
Input Voltage Range ( $V_{IN}$ )	$3.5\text{ V}$ to $6.0\text{ V}$ DC ( $6.5\text{ V}$ absolute max)
Quiescent Ground Current ( $I_Q$ )	$1.6\ \mu\text{A}$ typical ( $4.0\ \mu\text{A}$ max over $-40^\circ\text{C} \dots 125^\circ\text{C}$ )
Dropout Voltage ( $V_{DROP}$ )	$178\text{ mV}$ typ at $250\text{mA}$ / $70\text{ mV}$ at $100\text{mA}$
Maximum Output Current ( $I_{OUT}$ )	$250\text{ mA}$ continuous ( $350\text{ mA}$ peak current limit)
Output Capacitor Stability	Stable with standard $1.0\ \mu\text{F}$ ceramic capacitors

Pinout (TO-92 Package)

Looking at the flat front face of the TO-92 package with leads pointing downward:

text

        ┌─────────┐
        │  TO-92  │
        │ MCP1700 │
        │ -3302E  │
        └─┬───┬───┬─┘
          1   2   3
         GND VIN VOUT

Pin	Name	Type	Description
1	`GND`	Ground	Common system ground reference ( $0\text{ V}$ )
2	`VIN`	Power Input	Battery / DC Input ( $+3.5\text{ V}$ to $+6.0\text{ V}$ )
3	`VOUT`	Power Output	Regulated $+3.3\text{ V}$ DC output (Requires minimum $1.0\ \mu\text{F}$ ceramic capacitor)

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Output Voltage ( $25^\circ\text{C}$ )	$V_{OUT}$	3.234	3.300	3.366	V	$V_{IN} = 4.3\text{V}, I_L = 100\ \mu\text{A}$
Output Voltage (Full Temp)	$V_{OUT}$	3.201	3.300	3.399	V	$-40^\circ\text{C} \le T_J \le +125^\circ\text{C}$
Operating Input Voltage	$V_{IN}$	3.5	—	6.0	V	Normal operation
Quiescent Current	$I_Q$	—	1.6	4.0	µA	$I_L = 0\text{mA}, V_{IN} = 4.3\text{V}$
Dropout Voltage ( $250\text{mA}$ )	$V_{DROP}$	—	178	350	mV	$I_L = 250\text{mA}$
Dropout Voltage ( $100\text{mA}$ )	$V_{DROP}$	—	70	150	mV	$I_L = 100\text{mA}$
Line Regulation	$\Delta V_{OUT}$	—	0.05	0.20	%/V	$3.5\text{V} \le V_{IN} \le 6.0\text{V}, I_L = 100\ \mu\text{A}$
Load Regulation	$\Delta V_{OUT}$	—	0.5	1.5	%	$I_L = 1.0\text{mA} \dots 250\text{mA}$
Short-Circuit Current	$I_{SC}$	—	350	—	mA	$V_{OUT} = 0\text{V}$

Typical Application Circuit

text

  Li-Ion Battery (3.7V - 4.2V) or 3x AA Cells (4.5V)
           │
           ├───[ C_IN: 1.0µF Ceramic MLCC ]───┐
           │                                  │
       [Pin 2: VIN]                           │
      MCP1700-3302E                           │
       [Pin 1: GND] ──────────────────────────┼─── Common System GND
       [Pin 3: VOUT]                          │
           │                                  │
           ├───[ C_OUT: 1.0µF Ceramic MLCC ]──┘
           │
  Regulated +3.3V DC (Ultra-low quiescent standby for battery IoT MCUs)

Battery Life Comparison

Regulator	Quiescent Current ( $I_Q$ )	Battery Life (Idle 1000mAh Battery)
AMS1117-3.3	$5000\ \mu\text{A}$ ( $5\text{ mA}$ )	$\approx 200\text{ Hours}$ (8 days)
LP2950-3.3	$75\ \mu\text{A}$	$\approx 13,300\text{ Hours}$ (1.5 years)
MCP1700-3.3	$1.6\ \mu\text{A}$	$\approx 625,000\text{ Hours}$ (71 years)

Common mistakes

Exceeding the 6.0V input limit: The absolute maximum input rating of the MCP1700 is $6.5\text{V}$ . Connecting a $9\text{V}$ battery or $12\text{V}$ adapter directly will destroy the chip immediately.
Pinout difference from LP2950 / 78L05:
- MCP1700: Pin 1 = GND, Pin 2 = VIN, Pin 3 = VOUT
- LP2950: Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN Always double check the pin order before inserting into a breadboard or PCB.

Notes

Suffix Guide: 3302E denotes $+3.3\text{V}$ output, extended temp ( $-40^\circ\text{C} \dots 125^\circ\text{C}$ ); /TO designates through-hole TO-92 packaging.

Interface	3-Terminal Passive (GND, VIN, VOUT)
Package	TO-92 (3-pin through-hole) / SOT-23-3 / SOT-89-3