SG90 micro servo: specs
A 9 g micro hobby servo sold as an SG90, controlled by a PWM signal. The specs below are from the maker's (TowerPro) SG90 Analog product page, which has no PDF datasheet. The listing does not say whether the unit shipped is the analog or the digital SG90, so the figures may not match a digital unit.
Specs
| Spec | Value | Source |
|---|---|---|
| Weight | 9 g | source Specifications list |
| Dimensions | 23 x 12.2 x 29 mm | source Specifications list |
| Stall torque at 4.8 V | 1.8 kg/cm | source Specifications list |
| Gear type | POM gear set | source Specifications list |
| Operating speed at 4.8 V | 0.12 sec/60 degree in the specifications list; the product configure table on the same page shows 0.1 sec/60 deg | source Specifications list and PRODUCT CONFIGURE TABLE (the page is internally inconsistent) |
| Operating voltage | 4.8 V (one value; the page gives no range) | source Specifications list |
| Temperature range | 0 C to 55 C | source Specifications list |
| Dead band width | 1 us | source Specifications list |
| Servo wire length | 25 cm | source Specifications list |
| Servo plug | JR (fits JR and Futaba) | source Specifications list |
Power
| Value | Source | |
|---|---|---|
| Supply | 4.8 V as listed; power supply is 'Through External Adapter' per the page | source Specifications list |
Pinout
We don't publish a pin table for this part: no official source we could verify gives one. Check the labels printed on your module, and see the notes below.
The TowerPro SG90 Analog page lists a JR-type plug but does not give wire colours or pin order, so no pinout is published here. Check the wire order on your own servo.
Build with it
Project ideas for the SG90 micro servo. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Servo sweep test rig: The servo gets its own supply (the page says external adapter) with grounds joined to the Uno; the Uno only supplies the PWM signal. Learning project.
- Wi-Fi controlled latch demo: The ESP32 provides Wi-Fi and the PWM signal; the servo is powered from the separate 5 V rail of the breadboard supply, not from the ESP32. The page does not state the signal level the servo accepts, so test the 3.3 V PWM signal from the ESP32 on your own unit.
- Multi-servo mini arm: The PCA9685 generates the PWM for many servos over I2C and takes servo power on its own rail. Stall current is not on the maker page, so size the supply with margin and test one joint first.
- Motion-opened treat lid: The Uno reads the PIR output and drives one servo from a separate supply. Learning project; tell anyone nearby that a motion sensor is in use.
Common mistakes
- Powering the servo from a microcontroller board's logic pin: the page lists the power supply as through an external adapter, so use a separate supply with a common ground (source)
- Voltage: the maker page lists 4.8 V only and gives no maximum, so test on your own unit before using any other supply. The ideas below power the servo from a separate 5 V supply, a small step above the listed point; check that your unit is happy with it (source: link, Specifications list)
- Expecting the same torque and speed at other voltages: the figures are given at 4.8 V only (source)
Not covered by the official source
- No TowerPro PDF datasheet found; the maker's SG90 Analog product page is the source.
- Figures come only from the maker's SG90 Analog page; the SG90 Digital page lists the same figures except speed. On the Analog page speed is 0.12 s in its list and 0.1 s in its table; both are stated.
- Operating voltage is a single point (4.8 V), not a range.
- Stall torque at 6 V, stall current, pulse widths, signal level and wire colours are not on the page.
- The listing sells a 9 g micro servo; whether the shipped unit is analog or digital is not documented by the maker page. Check the unit's marking.